Eclipse Migration Initial Commit

.github/ISSUE_TEMPLATE.md

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+#### Issue Description
+
+Please describe our issue, along with:
+- expected behavior
+- encountered behavior
+
+#### Version Information
+
+Please indicate relevant versions, including, if relevant:
+
+* Deeplearning4j version
+* platform information (OS, etc)
+* CUDA version, if used
+* NVIDIA driver version, if in use
+
+#### Contributing
+
+If you'd like to help us fix the issue by contributing some code, but would
+like guidance or help in doing so, please mention it!

.github/PULL_REQUEST_TEMPLATE.md

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+## What changes were proposed in this pull request?
+
+(Please fill in changes proposed in this fix)
+
+## How was this patch tested?
+
+(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)
+
+## Quick checklist
+
+The following checklist helps ensure your PR is complete:
+
+- [ ] Reviewed the [Contributing Guidelines](https://github.com/deeplearning4j/deeplearning4j/blob/master/CONTRIBUTING.md) and followed the steps within.
+- [ ] Created tests for any significant new code additions.
+- [ ] Relevant tests for your changes are passing.
+- [ ] Ran mvn formatter:format (see [formatter instructions](http://code.revelc.net/formatter-maven-plugin/examples.html#Setting_Source_Files) for targeting your specific files).

.github/lock.yml

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+# Configuration for lock-threads - https://github.com/dessant/lock-threads
+
+# Number of days of inactivity before a closed issue or pull request is locked
+daysUntilLock: 30
+
+# Issues and pull requests with these labels will not be locked. Set to `[]` to disable
+exemptLabels: []
+
+# Label to add before locking, such as `outdated`. Set to `false` to disable
+lockLabel: false
+
+# Comment to post before locking. Set to `false` to disable
+lockComment: >
+  This thread has been automatically locked since there has not been
+  any recent activity after it was closed. Please open a new issue for
+  related bugs.
+
+# Assign `resolved` as the reason for locking. Set to `false` to disable
+setLockReason: false
+
+# Limit to only `issues` or `pulls`
+only: issues
+
+# Optionally, specify configuration settings just for `issues` or `pulls`
+# issues:
+#   exemptLabels:
+#     - help-wanted
+#   lockLabel: outdated
+
+# pulls:
+#   daysUntilLock: 30
+
+# Repository to extend settings from
+# _extends: repo

.gitignore

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+.DS_Store
+pom.xml.releaseBackup 
+target/
+dependency-reduced-pom.xml
+*.ser
+application.home_IS_UNDEFINEiD
+README.md~
+*.bin
+*.releaseBackup
+*.out
+*~
+.pydevproject
+release.properties
+.idea/
+*.iml
+*.prefs
+*.settings/*
+*.log
+.project
+.classpath
+metastore_db
+*.ipynb*
+!/dl4j-examples/tutorials/*.ipynb
+*-git.properties
+*.class
+*.jar
+*.war
+*.ear
+*.zip
+*.tar.gz
+*.rar
+hs_err_pid*
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+release.properties
+*dependency-reduced-pom.xml
+
+# Specific for Nd4j
+*.md5
+*.pom
+*.sha1
+*.ser
+*.so
+*.jpg
+*.png
+*.iml
+*.prefs
+*.dylib
+lib/
+.vs/
+.vscode/
+nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/resources/bin
+nd4j/nd4j-backends/nd4j-backend-impls/nd4j-native/src/test/resources/writeNumpy.csv
+nd4j/nd4j-backends/nd4j-tests/src/test/resources/tf_graphs/examples/**/data-all*
+nd4j/nd4j-backends/nd4j-tests/src/test/resources/tf_graphs/examples/**/checkpoint
+nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/onnx/
+nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/tensorflow/
+
+doc_sources/
+doc_sources_*
+
+*.pyc

CONTRIBUTING.md

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+# Contributing to Deeplearning4j
+
+Thanks for your interest in DL4J. Our goal is to bring fast, open-source deep learning to all JVM-based communities.
+
+
+## Getting Started
+
+Deeplearning4j's [open issues are here](https://github.com/deeplearning4j/deeplearning4j/issues). In time, we'll tag issues that would make a good first pull request for new contributors. An easy way to get started helping the project is to *file an issue*. You can do that on the Deeplearning4j issues page by clicking on the green button at the right. Issues can include bugs to fix, features to add, or documentation that looks outdated. 
+
+Note that you will need to [build dl4j from source](https://deeplearning4j.org/docs/latest/deeplearning4j-build-from-source)
+
+For some tips on contributing to open source, this [post is helpful](http://blog.smartbear.com/programming/14-ways-to-contribute-to-open-source-without-being-a-programming-genius-or-a-rock-star/).
+
+## Contributions
+
+Deeplearning4j welcomes contributions from everyone.
+
+Contributions to Deeplearning4j should be made in the form of GitHub pull requests. Each pull request will
+be reviewed by a core contributor (someone with permission to land patches) and either landed in the
+main tree or given feedback for changes that would be required.
+
+## Pull Request Checklist
+
+- Branch from the master branch and, if needed, rebase to the current master
+  branch before submitting your pull request. If it doesn't merge cleanly with
+  master you may be asked to rebase your changes.
+
+- Commits should be as small as possible, while ensuring that each commit is
+  correct independently (i.e., each commit should compile and pass tests). 
+
+- Don't put submodule updates in your pull request unless they are to landed
+  commits.
+
+- If your patch is not getting reviewed or you need a specific person to review
+  it, you can @-reply a reviewer asking for a review in the pull request or a
+  comment.
+
+- Work-in-progress pull requests are welcome. Please prefix them with `[WIP]` to tell the continuous integration (CI) backend not to run tests/checks on them (until that tag is removed and another commit is pushed up).
+
+- Add tests relevant to the fixed bug or new feature.  
+
+## Conduct & License
+
+We follow the [Rust Code of Conduct](http://www.rust-lang.org/conduct.html).
+
+All code in this repository is released under the Apache Software Foundation License, 2.0, and by contributing to this repository, you agree to release that contribution under that same license. 

Jenkinsfile

@@ -0,0 +1,26 @@
+#!groovy
+
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+/*
+    To redefine some job/run parameters,
+    please provide arguments to jenkinsBuilder step.
+    Example: jenkinsBuilder platforms: []
+ */
+
+jenkinsBuilder()
+

LICENSE

@@ -0,0 +1,384 @@
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+##########################
+
+Keras code
+
+Auto-generated documentation: https://github.com/deeplearning4j/deeplearning4j/blob/master/docs/doc_generator.py
+
+COPYRIGHT
+
+All contributions by François Chollet:
+Copyright (c) 2015 - 2018, François Chollet.
+All rights reserved.
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+furnished to do so, subject to the following conditions:
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+copies or substantial portions of the Software.
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+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+
+##########################
+
+OpenCSV Code
+
+CSVParser: https://github.com/deeplearning4j/deeplearning4j/blob/master/datavec/datavec-api/src/main/java/org/datavec/api/records/reader/impl/csv/SerializableCSVParser.java
+
+Apache 2.0 License
+
+All contributions by Bytecode Pty Ltd.
+Copyright 2005 Bytecode Pty Ltd.
+All rights reserved.
+
+
+##########################
+
+Aeron Code
+
+Modifed Code: nd4j/nd4j-serde/nd4j-aeron/src/main/java/org/nd4j/aeron/ipc/AeronUtil.java
+
+Copyright 2014 - 2016 Real Logic Ltd. All rights reserved.
+
+Apache License, Version 2.0
+
+
+##########################
+
+cnpy Code
+
+Forked Code: libnd4j/include/cnpy/
+
+The MIT License
+
+Copyright (c) Carl Rogers, 2011
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
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+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+
+##########################
+
+Protocol Buffers Code
+
+Codebase: nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/protobuf/tf/google/protobuf/
+
+Protocol Buffers - Google's data interchange format
+Copyright 2008 Google Inc.  All rights reserved.
+https://developers.google.com/protocol-buffers/
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+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
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+distribution.
+    * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
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+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+##########################
+
+ONNX Code
+
+Protocol Buffers: nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/protobuf/onnx/
+
+Copyright (c) Facebook Inc. and Microsoft Corporation. All rights reserved.
+
+Licensed under the MIT license.
+
+
+##########################
+
+TensorFlow Code
+
+Protocol Buffers: nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/protobuf/tf/tensorflow/core/
+Operations: libnd4j/include/ops/declarable/generic/parity_ops/
+
+Copyright 2015-2017 The TensorFlow Authors. All rights reserved.
+
+Apache License, Version 2.0
+
+
+##########################
+
+Ansj Code
+
+Codebase: deeplearning4j/deeplearning4j-nlp-parent/deeplearning4j-nlp-chinese/src/main/java/org/ansj/
+Resources: deeplearning4j/deeplearning4j-nlp-parent/deeplearning4j-nlp-chinese/src/main/resources/
+
+Copyright 2011-2016 ansj_seg. All rights reserved.
+
+Apache License, Version 2.0
+
+
+##########################
+
+Kuromoji Code
+
+Codebase: deeplearning4j/deeplearning4j-nlp-parent/deeplearning4j-nlp-japanese/src/main/java/com/atilika/kuromoji/
+
+Copyright (c) 2010-2015 Atilika Inc. and contributors. All rights reserved.
+
+Apache License, Version 2.0

README.md

@@ -0,0 +1,35 @@
+# Monorepo of Deeplearning4j
+
+Welcome to the new monorepo of Deeplearning4j that contains the source code for all the following projects, in addition to the original repository of Deeplearning4j moved to [deeplearning4j](deeplearning4j):
+
+ * https://github.com/deeplearning4j/libnd4j
+ * https://github.com/deeplearning4j/nd4j
+ * https://github.com/deeplearning4j/datavec
+ * https://github.com/deeplearning4j/arbiter
+ * https://github.com/deeplearning4j/nd4s
+ * https://github.com/deeplearning4j/gym-java-client
+ * https://github.com/deeplearning4j/rl4j
+ * https://github.com/deeplearning4j/scalnet
+ * https://github.com/deeplearning4j/pydl4j
+ * https://github.com/deeplearning4j/jumpy
+ * https://github.com/deeplearning4j/pydatavec
+ 
+
+To build everything, we can use commands like
+```
+./change-cuda-versions.sh x.x
+./change-scala-versions.sh 2.xx
+./change-spark-versions.sh x
+mvn clean install -Dmaven.test.skip -Dlibnd4j.cuda=x.x -Dlibnd4j.compute=xx
+```
+or
+```
+mvn -B -V -U clean install -pl '!jumpy,!pydatavec,!pydl4j' -Dlibnd4j.platform=linux-x86_64 -Dlibnd4j.chip=cuda -Dlibnd4j.cuda=9.2 -Dlibnd4j.compute=<your GPU CC> -Djavacpp.platform=linux-x86_64 -Dmaven.test.skip=true
+```
+
+An example of GPU "CC" or compute capability is 61 for Titan X Pascal.
+
+# Want some examples?
+We have separate repository with various examples available: https://github.com/deeplearning4j/dl4j-examples
+
+In the examples repo, you'll also find a tutorial series in Zeppelin: https://github.com/deeplearning4j/dl4j-examples/tree/master/tutorials

arbiter/.github/CONTRIBUTING.md

@@ -0,0 +1,15 @@
+## Contribute
+
+1. Check for open issues, or open a new issue to start a discussion around a feature idea or a bug.
+2. If you feel uncomfortable or uncertain about an issue or your changes, feel free to contact us on Gitter using the link above.
+3. Fork [the repository](https://github.com/deeplearning4j/Arbiter.git) on GitHub to start making your changes to the **master** branch (or branch off of it).
+4. Write a test, which shows that the bug was fixed or that the feature works as expected.
+5. Note the repository follows
+   the [Google Java style](https://google.github.io/styleguide/javaguide.html)
+   with two modifications: 120-char column wrap and 4-spaces indentation. You
+   can format your code to this format by typing `mvn formatter:format` in the
+   subproject you work on, by using the `contrib/formatter.xml` at the root of
+   the repository to configure the Eclipse formatter, or by [using the INtellij
+   plugin](https://github.com/HPI-Information-Systems/Metanome/wiki/Installing-the-google-styleguide-settings-in-intellij-and-eclipse).
+
+6. Send a pull request, and bug us on Gitter until it gets merged and published.

arbiter/.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,19 @@
+#### Issue Description
+
+Please describe your issue, along with:
+- expected behavior
+- encountered behavior
+
+#### Version Information
+
+Please indicate relevant versions, including, if relevant:
+
+* Deeplearning4j version
+* platform information (OS, etc)
+* CUDA version, if used
+* NVIDIA driver version, if in use
+
+#### Contributing
+
+If you'd like to help us fix the issue by contributing some code, but would
+like guidance or help in doing so, please mention it!

arbiter/.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,10 @@
+## What changes were proposed in this pull request?
+
+(Please fill in changes proposed in this fix)
+
+## How was this patch tested?
+
+(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)
+
+Please review
+https://github.com/deeplearning4j/deeplearning4j/blob/master/CONTRIBUTING.md before opening a pull request.

arbiter/.travis.yml

@@ -0,0 +1,24 @@
+branches:
+  only:
+    - master
+notifications:
+  email: false
+dist: trusty
+sudo: false
+cache:
+  directories:
+    - $HOME/.m2
+language: java
+jdk:
+  - openjdk8
+matrix:
+  include:
+    - os: linux
+      env: OS=linux-x86_64 SCALA=2.10
+      install: true
+      script: bash ./ci/build-linux-x86_64.sh
+    - os: linux
+      env: OS=linux-x86_64 SCALA=2.11
+      install: true
+      script: bash ./ci/build-linux-x86_64.sh
+

arbiter/README.md

@@ -0,0 +1,45 @@
+# Arbiter
+
+A tool dedicated to tuning (hyperparameter optimization) of machine learning models. Part of the DL4J Suite of Machine Learning / Deep Learning tools for the enterprise.
+
+
+## Modules
+Arbiter contains the following modules:
+
+- arbiter-core: Defines the API and core functionality, and also contains functionality for the Arbiter UI
+- arbiter-deeplearning4j: For hyperparameter optimization of DL4J models (MultiLayerNetwork and ComputationGraph networks)
+
+
+## Hyperparameter Optimization Functionality
+
+The open-source version of Arbiter currently defines two methods of hyperparameter optimization:
+
+- Grid search
+- Random search
+
+For optimization of complex models such as neural networks (those with more than a few hyperparameters), random search is superior to grid search, though Bayesian hyperparameter optimization schemes 
+For a comparison of random and grid search methods, see [Random Search for Hyper-parameter Optimization (Bergstra and Bengio, 2012)](http://www.jmlr.org/papers/volume13/bergstra12a/bergstra12a.pdf).
+
+### Core Concepts and Classes in Arbiter for Hyperparameter Optimization
+
+In order to conduct hyperparameter optimization in Arbiter, it is necessary for the user to understand and define the following:
+
+- **Parameter Space**: A ```ParameterSpace<P>``` specifies the type and allowable values of hyperparameters for a model configuration of type ```P```. For example, ```P``` could be a MultiLayerConfiguration for DL4J
+- **Candidate Generator**: A ```CandidateGenerator<C>``` is used to generate candidate models configurations of some type ```C```. The following implementations are defined in arbiter-core:
+    - ```RandomSearchCandidateGenerator```
+    - ```GridSearchCandidateGenerator```
+- **Score Function**: A ```ScoreFunction<M,D>``` is used to score a model of type ```M``` given data of type ```D```. For example, in DL4J a score function might be used to calculate the classification accuracy from a DataSetIterator
+    - A key concept here is that they score is a single numerical (double precision) value that we either want to minimize or maximize - this is the goal of hyperparameter optimization
+- **Termination Conditions**: One or more ```TerminationCondition``` instances must be provided to the ```OptimizationConfiguration```. ```TerminationCondition``` instances are used to control when hyperparameter optimization should be stopped. Some built-in termination conditions:
+    - ```MaxCandidatesCondition```: Terminate if more than the specified number of candidate hyperparameter configurations have been executed
+    - ```MaxTimeCondition```: Terminate after a specified amount of time has elapsed since starting the optimization
+- **Result Saver**: The ```ResultSaver<C,M,A>``` interface is used to specify how the results of each hyperparameter optimization run should be saved. For example, whether saving should be done to local disk, to a database, to HDFS, or simply stored in memory.
+    - Note that ```ResultSaver.saveModel``` method returns a ```ResultReference``` object, which provides a mechanism for re-loading both the model and score from wherever it may be saved.
+- **Optimization Configuration**: An ```OptimizationConfiguration<C,M,D,A>``` ties together the above configuration options in a fluent (builder) pattern.
+- **Candidate Executor**: The ```CandidateExecutor<C,M,D,A>``` interface provides a layer of abstraction between the configuration and execution of each instance of learning. Currently, the only option is the ```LocalCandidateExecutor```, which is used to execute learning on a single machine (in the current JVM). In principle, other execution methods (for example, on Spark or cloud computing machines) could be implemented.
+- **Optimization Runner**: The ```OptimizationRunner``` uses an ```OptimizationConfiguration``` and a ```CandidateExecutor``` to actually run the optimization, and save the results.
+
+
+### Optimization of DeepLearning4J Models
+
+(This section: forthcoming)

arbiter/arbiter-core/pom.xml

@@ -0,0 +1,83 @@
+<!--~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  ~ Copyright (c) 2015-2018 Skymind, Inc.
+  ~
+  ~ This program and the accompanying materials are made available under the
+  ~ terms of the Apache License, Version 2.0 which is available at
+  ~ https://www.apache.org/licenses/LICENSE-2.0.
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+  ~ WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+  ~ License for the specific language governing permissions and limitations
+  ~ under the License.
+  ~
+  ~ SPDX-License-Identifier: Apache-2.0
+  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>arbiter</artifactId>
+        <groupId>org.deeplearning4j</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>arbiter-core</artifactId>
+    <packaging>jar</packaging>
+
+    <name>arbiter-core</name>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.nd4j</groupId>
+            <artifactId>nd4j-api</artifactId>
+            <version>${nd4j.version}</version>
+            <exclusions>
+              <exclusion>
+                <groupId>com.google.code.findbugs</groupId>
+                <artifactId>*</artifactId>
+              </exclusion>
+            </exclusions>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons.lang.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-math3</artifactId>
+            <version>${commons.math.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>${slf4j.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>${logback.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+
+        <!-- ND4J Shaded Jackson Dependency -->
+        <dependency>
+            <groupId>org.nd4j</groupId>
+            <artifactId>jackson</artifactId>
+            <version>${nd4j.version}</version>
+        </dependency>
+    </dependencies>
+</project>

arbiter/arbiter-core/src/assembly/bin.xml

@@ -0,0 +1,91 @@
+<!--~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  ~ Copyright (c) 2015-2018 Skymind, Inc.
+  ~
+  ~ This program and the accompanying materials are made available under the
+  ~ terms of the Apache License, Version 2.0 which is available at
+  ~ https://www.apache.org/licenses/LICENSE-2.0.
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+  ~ WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+  ~ License for the specific language governing permissions and limitations
+  ~ under the License.
+  ~
+  ~ SPDX-License-Identifier: Apache-2.0
+  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-->
+
+<assembly>
+	<id>bin</id>
+	<!--  START SNIPPET: formats  -->
+	<formats>
+		<format>tar.gz</format>
+<!--
+		<format>tar.bz2</format>
+		<format>zip</format>
+-->		
+	</formats>
+	<!--  END SNIPPET: formats  -->
+	
+<dependencySets>
+    <dependencySet>
+    <outputDirectory>lib</outputDirectory>
+      <includes>
+        <include>*:jar:*</include>
+      </includes>
+      <excludes>
+        <exclude>*:sources</exclude>
+      </excludes>
+    </dependencySet>
+  </dependencySets>	
+	
+	<!--  START SNIPPET: fileSets  -->
+	<fileSets>
+		<fileSet>
+			<includes>
+				<include>readme.txt</include>
+			</includes>
+		</fileSet>
+
+		<fileSet>
+			<directory>src/main/resources/bin/</directory>
+			<outputDirectory>bin</outputDirectory>
+			<includes>
+				<include>arbiter</include>
+			</includes>
+			<lineEnding>unix</lineEnding>
+			<fileMode>0755</fileMode>
+		</fileSet>
+
+		<fileSet>
+			<directory>examples</directory>
+			<outputDirectory>examples</outputDirectory>
+			<!--
+				<lineEnding>unix</lineEnding>
+				http://stackoverflow.com/questions/2958282/stranges-files-in-my-assembly-since-switching-to-lineendingunix-lineending
+			-->
+		</fileSet>
+
+		
+<!--		
+		<fileSet>
+			<directory>src/bin</directory>
+			<outputDirectory>bin</outputDirectory>
+			<includes>
+			<include>hello</include>
+			</includes>
+			<lineEnding>unix</lineEnding>
+			<fileMode>0755</fileMode>
+		</fileSet>
+-->
+
+		<fileSet>
+			<directory>target</directory>
+			<outputDirectory>./</outputDirectory>
+			<includes>
+				<include>*.jar</include>
+			</includes>
+		</fileSet>
+		
+	</fileSets>
+	<!--  END SNIPPET: fileSets  -->
+</assembly>

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/AbstractParameterSpace.java

@@ -0,0 +1,74 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api;
+
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Created by Alex on 23/07/2017.
+ */
+public abstract class AbstractParameterSpace<T> implements ParameterSpace<T> {
+
+    @Override
+    public Map<String, ParameterSpace> getNestedSpaces() {
+        Map<String, ParameterSpace> m = new LinkedHashMap<>();
+
+        //Need to manually build and walk the class heirarchy...
+        Class<?> currClass = this.getClass();
+        List<Class<?>> classHeirarchy = new ArrayList<>();
+        while (currClass != Object.class) {
+            classHeirarchy.add(currClass);
+            currClass = currClass.getSuperclass();
+        }
+
+        for (int i = classHeirarchy.size() - 1; i >= 0; i--) {
+            //Use reflection here to avoid a mass of boilerplate code...
+            Field[] allFields = classHeirarchy.get(i).getDeclaredFields();
+
+            for (Field f : allFields) {
+
+                String name = f.getName();
+                Class<?> fieldClass = f.getType();
+                boolean isParamSpacefield = ParameterSpace.class.isAssignableFrom(fieldClass);
+
+                if (!isParamSpacefield) {
+                    continue;
+                }
+
+                f.setAccessible(true);
+
+                ParameterSpace<?> p;
+                try {
+                    p = (ParameterSpace<?>) f.get(this);
+                } catch (IllegalAccessException e) {
+                    throw new RuntimeException(e);
+                }
+
+                if (p != null) {
+                    m.put(name, p);
+                }
+            }
+        }
+
+        return m;
+    }
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/Candidate.java

@@ -0,0 +1,57 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import org.deeplearning4j.arbiter.optimize.generator.util.SerializedSupplier;
+import org.nd4j.linalg.function.Supplier;
+
+import java.io.Serializable;
+import java.util.Map;
+
+/**
+ * Candidate: a proposed hyperparameter configuration.
+ * Also includes a map for data parameters, to configure things like data preprocessing, etc.
+ */
+@Data
+@AllArgsConstructor
+public class Candidate<C> implements Serializable {
+
+    private Supplier<C> supplier;
+    private int index;
+    private double[] flatParameters;
+    private Map<String, Object> dataParameters;
+    private Exception exception;
+
+    public Candidate(C value, int index, double[] flatParameters, Map<String,Object> dataParameters, Exception e) {
+        this(new SerializedSupplier<C>(value), index, flatParameters, dataParameters, e);
+    }
+
+    public Candidate(C value, int index, double[] flatParameters) {
+        this(new SerializedSupplier<C>(value), index, flatParameters);
+    }
+
+    public Candidate(Supplier<C> value, int index, double[] flatParameters) {
+        this(value, index, flatParameters, null, null);
+    }
+
+    public C getValue(){
+        return supplier.get();
+    }
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/CandidateGenerator.java

@@ -0,0 +1,68 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api;
+
+import org.deeplearning4j.arbiter.optimize.generator.GridSearchCandidateGenerator;
+import org.deeplearning4j.arbiter.optimize.generator.RandomSearchGenerator;
+import org.nd4j.shade.jackson.annotation.JsonInclude;
+import org.nd4j.shade.jackson.annotation.JsonSubTypes;
+import org.nd4j.shade.jackson.annotation.JsonTypeInfo;
+
+/**
+ * A CandidateGenerator proposes candidates (i.e., hyperparameter configurations) for evaluation.
+ * This abstraction allows for different ways of generating the next configuration to test; for example,
+ * random search, grid search, Bayesian optimization methods, etc.
+ *
+ * @author Alex Black
+ */
+@JsonInclude(JsonInclude.Include.NON_NULL)
+@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@class")
+public interface CandidateGenerator {
+
+    /**
+     * Is this candidate generator able to generate more candidates? This will always return true in some
+     * cases, but some search strategies have a limit (grid search, for example)
+     */
+    boolean hasMoreCandidates();
+
+    /**
+     * Generate a candidate hyperparameter configuration
+     */
+    Candidate getCandidate();
+
+    /**
+     * Report results for the candidate generator.
+     *
+     * @param result The results to report
+     */
+    void reportResults(OptimizationResult result);
+
+    /**
+     * @return Get the parameter space for this candidate generator
+     */
+    ParameterSpace<?> getParameterSpace();
+
+    /**
+     * @param rngSeed Set the random number generator seed for the candidate generator
+     */
+    void setRngSeed(long rngSeed);
+
+    /**
+     * @return The type (class) of the generated candidates
+     */
+    Class<?> getCandidateType();
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/OptimizationResult.java

@@ -0,0 +1,60 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api;
+
+import lombok.Data;
+import org.deeplearning4j.arbiter.optimize.api.saving.ResultReference;
+import org.deeplearning4j.arbiter.optimize.runner.CandidateInfo;
+import org.nd4j.shade.jackson.annotation.JsonIgnoreProperties;
+import org.nd4j.shade.jackson.annotation.JsonProperty;
+import org.nd4j.shade.jackson.annotation.JsonTypeInfo;
+
+import java.io.Serializable;
+
+/**
+ * An optimization result represents the results of an optimization run, including the canditate configuration, the
+ * trained model, the score for that model, and index of the model
+ *
+ * @author Alex Black
+ */
+@Data
+@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@class")
+@JsonIgnoreProperties({"resultReference"})
+public class OptimizationResult implements Serializable {
+    @JsonProperty
+    private Candidate candidate;
+    @JsonProperty
+    private Double score;
+    @JsonProperty
+    private int index;
+    @JsonProperty
+    private Object modelSpecificResults;
+    @JsonProperty
+    private CandidateInfo candidateInfo;
+    private ResultReference resultReference;
+
+
+    public OptimizationResult(Candidate candidate, Double score, int index, Object modelSpecificResults,
+                    CandidateInfo candidateInfo, ResultReference resultReference) {
+        this.candidate = candidate;
+        this.score = score;
+        this.index = index;
+        this.modelSpecificResults = modelSpecificResults;
+        this.candidateInfo = candidateInfo;
+        this.resultReference = resultReference;
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/ParameterSpace.java

@@ -0,0 +1,81 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api;
+
+import org.nd4j.shade.jackson.annotation.JsonIgnore;
+import org.nd4j.shade.jackson.annotation.JsonInclude;
+import org.nd4j.shade.jackson.annotation.JsonTypeInfo;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * ParameterSpace: defines the acceptable ranges of values a given parameter may take.
+ * Note that parameter spaces can be simple (like {@code ParameterSpace<Double>}) or complicated, including
+ * multiple nested ParameterSpaces
+ *
+ * @author Alex Black
+ */
+@JsonInclude(JsonInclude.Include.NON_NULL)
+@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@class")
+public interface ParameterSpace<P> {
+
+    /**
+     * Generate a candidate given a set of values. These values are then mapped to a specific candidate, using some
+     * mapping function (such as the prior probability distribution)
+     *
+     * @param parameterValues A set of values, each in the range [0,1], of length {@link #numParameters()}
+     */
+    P getValue(double[] parameterValues);
+
+    /**
+     * Get the total number of parameters (hyperparameters) to be optimized. This includes optional parameters from
+     * different parameter subpaces. (Thus, not every parameter may be used in every candidate)
+     *
+     * @return Number of hyperparameters to be optimized
+     */
+    int numParameters();
+
+    /**
+     * Collect a list of parameters, recursively. Note that leaf parameters are parameters that do not have any
+     * nested parameter spaces
+     */
+    List<ParameterSpace> collectLeaves();
+
+    /**
+     * Get a list of nested parameter spaces by name. Note that the returned parameter spaces may in turn have further
+     * nested parameter spaces. The map should be empty for leaf parameter spaces
+     *
+     * @return  A map of nested parameter spaces
+     */
+    Map<String, ParameterSpace> getNestedSpaces();
+
+    /**
+     * Is this ParameterSpace a leaf? (i.e., does it contain other ParameterSpaces internally?)
+     */
+    @JsonIgnore
+    boolean isLeaf();
+
+    /**
+     * For leaf ParameterSpaces: set the indices of the leaf ParameterSpace.
+     * Expects input of length {@link #numParameters()}. Throws exception if {@link #isLeaf()} is false.
+     *
+     * @param indices Indices to set. Length should equal {@link #numParameters()}
+     */
+    void setIndices(int... indices);
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/TaskCreator.java

@@ -0,0 +1,62 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api;
+
+import org.deeplearning4j.arbiter.optimize.api.data.DataProvider;
+import org.deeplearning4j.arbiter.optimize.api.data.DataSource;
+import org.deeplearning4j.arbiter.optimize.api.score.ScoreFunction;
+import org.deeplearning4j.arbiter.optimize.runner.IOptimizationRunner;
+import org.deeplearning4j.arbiter.optimize.runner.listener.StatusListener;
+
+import java.util.List;
+import java.util.Properties;
+import java.util.concurrent.Callable;
+
+/**
+ * The TaskCreator is used to take a candidate configuration, data provider and score function, and create something
+ * that can be executed as a Callable
+ *
+ * @author Alex Black
+ */
+public interface TaskCreator {
+
+    /**
+     * Generate a callable that can be executed to conduct the training of this model (given the model configuration)
+     *
+     * @param candidate       Candidate (model) configuration to be trained
+     * @param dataProvider    DataProvider, for the data
+     * @param scoreFunction   Score function to be used to evaluate the model
+     * @param statusListeners Status listeners, that can be used for callbacks (to UI, for example)
+     * @return A callable that returns an OptimizationResult, once optimization is complete
+     */
+    @Deprecated
+    Callable<OptimizationResult> create(Candidate candidate, DataProvider dataProvider, ScoreFunction scoreFunction,
+                                        List<StatusListener> statusListeners, IOptimizationRunner runner);
+
+    /**
+     * Generate a callable that can be executed to conduct the training of this model (given the model configuration)
+     *
+     * @param candidate            Candidate (model) configuration to be trained
+     * @param dataSource           Data source
+     * @param dataSourceProperties Properties (may be null) for the data source
+     * @param scoreFunction        Score function to be used to evaluate the model
+     * @param statusListeners      Status listeners, that can be used for callbacks (to UI, for example)
+     * @return A callable that returns an OptimizationResult, once optimization is complete
+     */
+    Callable<OptimizationResult> create(Candidate candidate, Class<? extends DataSource> dataSource, Properties dataSourceProperties,
+                                        ScoreFunction scoreFunction, List<StatusListener> statusListeners, IOptimizationRunner runner);
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/TaskCreatorProvider.java

@@ -0,0 +1,43 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class TaskCreatorProvider {
+
+    private static Map<Class<? extends ParameterSpace>, Class<? extends TaskCreator>> map = new HashMap<>();
+
+    public synchronized static TaskCreator defaultTaskCreatorFor(Class<? extends ParameterSpace> paramSpaceClass){
+        Class<? extends TaskCreator> c = map.get(paramSpaceClass);
+        try {
+            if(c == null){
+                return null;
+            }
+            return c.newInstance();
+        } catch (Exception e){
+            throw new RuntimeException("Could not create new instance of task creator class: " + c, e);
+        }
+    }
+
+    public synchronized static void registerDefaultTaskCreatorClass(Class<? extends ParameterSpace> spaceClass,
+                                                                    Class<? extends TaskCreator> creatorClass){
+        map.put(spaceClass, creatorClass);
+    }
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/adapter/ParameterSpaceAdapter.java

@@ -0,0 +1,75 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api.adapter;
+
+import lombok.AllArgsConstructor;
+import org.deeplearning4j.arbiter.optimize.api.ParameterSpace;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * An abstract class used for adapting one type into another. Subclasses of this need to merely implement 2 simple methods
+ *
+ * @param <F> Type to convert from
+ * @param <T> Type to convert to
+ * @author Alex Black
+ */
+@AllArgsConstructor
+public abstract class ParameterSpaceAdapter<F, T> implements ParameterSpace<T> {
+
+
+    protected abstract T convertValue(F from);
+
+    protected abstract ParameterSpace<F> underlying();
+
+
+    @Override
+    public T getValue(double[] parameterValues) {
+        return convertValue(underlying().getValue(parameterValues));
+    }
+
+    @Override
+    public int numParameters() {
+        return underlying().numParameters();
+    }
+
+    @Override
+    public List<ParameterSpace> collectLeaves() {
+        return underlying().collectLeaves();
+    }
+
+    @Override
+    public Map<String, ParameterSpace> getNestedSpaces() {
+        return underlying().getNestedSpaces();
+    }
+
+    @Override
+    public boolean isLeaf() {
+        return underlying().isLeaf();
+    }
+
+    @Override
+    public void setIndices(int... indices) {
+        underlying().setIndices(indices);
+    }
+
+    @Override
+    public String toString() {
+        return underlying().toString();
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/data/DataProvider.java

@@ -0,0 +1,54 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api.data;
+
+import org.nd4j.shade.jackson.annotation.JsonInclude;
+import org.nd4j.shade.jackson.annotation.JsonTypeInfo;
+
+import java.io.Serializable;
+import java.util.Map;
+
+/**
+ * DataProvider interface abstracts out the providing of data
+ * @deprecated Use {@link DataSource}
+ */
+@JsonInclude(JsonInclude.Include.NON_NULL)
+@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@class")
+@Deprecated
+public interface DataProvider extends Serializable {
+
+    /**
+     * Get training data given some parameters for the data.
+     * Data parameters map is used to specify things like batch
+     * size data preprocessing
+     *
+     * @param dataParameters Parameters for data. May be null or empty for default data
+     * @return training data
+     */
+    Object trainData(Map<String, Object> dataParameters);
+
+    /**
+     * Get training data given some parameters for the data. Data parameters map is used to specify things like batch
+     * size data preprocessing
+     *
+     * @param dataParameters Parameters for data. May be null or empty for default data
+     * @return training data
+     */
+    Object testData(Map<String, Object> dataParameters);
+
+    Class<?> getDataType();
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/data/DataSetIteratorFactoryProvider.java

@@ -0,0 +1,89 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api.data;
+
+import lombok.Data;
+import org.nd4j.linalg.dataset.api.iterator.DataSetIteratorFactory;
+
+import java.util.Map;
+
+/**
+ * This is a {@link DataProvider} for
+ * an {@link DataSetIteratorFactory} which
+ * based on a key of {@link DataSetIteratorFactoryProvider#FACTORY_KEY}
+ * will create {@link org.nd4j.linalg.dataset.api.iterator.DataSetIterator}
+ * for use with arbiter.
+ *
+ * This {@link DataProvider} is mainly meant for use for command line driven
+ * applications.
+ *
+ * @author Adam Gibson
+ */
+@Data
+public class DataSetIteratorFactoryProvider implements DataProvider {
+
+    public final static String FACTORY_KEY = "org.deeplearning4j.arbiter.data.data.factory";
+
+    /**
+     * Get training data given some parameters for the data.
+     * Data parameters map is used to specify things like batch
+     * size data preprocessing
+     *
+     * @param dataParameters Parameters for data. May be null or empty for default data
+     * @return training data
+     */
+    @Override
+    public DataSetIteratorFactory trainData(Map<String, Object> dataParameters) {
+        return create(dataParameters);
+    }
+
+    /**
+     * Get training data given some parameters for the data. Data parameters map
+     * is used to specify things like batch
+     * size data preprocessing
+     *
+     * @param dataParameters Parameters for data. May be null or empty for default data
+     * @return training data
+     */
+    @Override
+    public DataSetIteratorFactory testData(Map<String, Object> dataParameters) {
+        return create(dataParameters);
+    }
+
+    @Override
+    public Class<?> getDataType() {
+        return DataSetIteratorFactory.class;
+    }
+
+    private DataSetIteratorFactory create(Map<String, Object> dataParameters) {
+        if (dataParameters == null)
+            throw new IllegalArgumentException(
+                            "Data parameters is null. Please specify a class name to create a dataset iterator.");
+        if (!dataParameters.containsKey(FACTORY_KEY))
+            throw new IllegalArgumentException(
+                            "No data set iterator factory class found. Please specify a class name with key "
+                                            + FACTORY_KEY);
+        String value = dataParameters.get(FACTORY_KEY).toString();
+        try {
+            Class<? extends DataSetIteratorFactory> clazz =
+                            (Class<? extends DataSetIteratorFactory>) Class.forName(value);
+            return clazz.newInstance();
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/data/DataSource.java

@@ -0,0 +1,57 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api.data;
+
+import java.io.Serializable;
+import java.util.Properties;
+
+/**
+ * DataSource: defines where the data should come from for training and testing.
+ * Note that implementations must have a no-argument contsructor
+ *
+ * @author Alex Black
+ */
+public interface DataSource extends Serializable {
+
+    /**
+     * Configure the current data source with the specified properties
+     * Note: These properties are fixed for the training instance, and are optionally provided by the user
+     * at the configuration stage.
+     * The properties could be anything - and are usually specific to each DataSource implementation.
+     * For example, values such as batch size could be set using these properties
+     * @param properties Properties to apply to the data source instance
+     */
+    void configure(Properties properties);
+
+    /**
+     * Get test data to be used for the optimization. Usually a DataSetIterator or MultiDataSetIterator
+     */
+    Object trainData();
+
+    /**
+     * Get test data to be used for the optimization. Usually a DataSetIterator or MultiDataSetIterator
+     */
+    Object testData();
+
+    /**
+     * The type of data returned by {@link #trainData()} and {@link #testData()}.
+     * Usually DataSetIterator or MultiDataSetIterator
+     * @return Class of the objects returned by trainData and testData
+     */
+    Class<?> getDataType();
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/evaluation/ModelEvaluator.java

@@ -0,0 +1,40 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api.evaluation;
+
+import org.deeplearning4j.arbiter.optimize.api.data.DataProvider;
+
+import java.io.Serializable;
+import java.util.List;
+
+/**
+ * ModelEvaluator: Used to conduct additional evaluation.
+ * For example, this may be classification performance on a test set or similar
+ */
+public interface ModelEvaluator extends Serializable {
+    Object evaluateModel(Object model, DataProvider dataProvider);
+
+    /**
+     * @return The model types supported by this class
+     */
+    List<Class<?>> getSupportedModelTypes();
+
+    /**
+     * @return The datatypes supported by this class
+     */
+    List<Class<?>> getSupportedDataTypes();
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/saving/InMemoryResultSaver.java

@@ -0,0 +1,63 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api.saving;
+
+import lombok.AllArgsConstructor;
+import lombok.NoArgsConstructor;
+import org.deeplearning4j.arbiter.optimize.api.OptimizationResult;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * A simple class to store optimization results in-memory.
+ * Not recommended for large (or a large number of) models.
+ */
+@NoArgsConstructor
+public class InMemoryResultSaver implements ResultSaver {
+    @Override
+    public ResultReference saveModel(OptimizationResult result, Object modelResult) throws IOException {
+        return new InMemoryResult(result, modelResult);
+    }
+
+    @Override
+    public List<Class<?>> getSupportedCandidateTypes() {
+        return Collections.<Class<?>>singletonList(Object.class);
+    }
+
+    @Override
+    public List<Class<?>> getSupportedModelTypes() {
+        return Collections.<Class<?>>singletonList(Object.class);
+    }
+
+    @AllArgsConstructor
+    private static class InMemoryResult implements ResultReference {
+        private OptimizationResult result;
+        private Object modelResult;
+
+        @Override
+        public OptimizationResult getResult() throws IOException {
+            return result;
+        }
+
+        @Override
+        public Object getResultModel() throws IOException {
+            return modelResult;
+        }
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/saving/ResultReference.java

@@ -0,0 +1,37 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api.saving;
+
+import org.deeplearning4j.arbiter.optimize.api.OptimizationResult;
+import org.nd4j.shade.jackson.annotation.JsonTypeInfo;
+
+import java.io.IOException;
+
+/**
+ * Idea: We can't store all results in memory in general (might have thousands of candidates with millions of
+ * parameters each)
+ * So instead: return a reference to the saved result. Idea is that the result may be saved to disk or a database,
+ * and we can easily load it back into memory (if/when required) using the getResult() method
+ */
+@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@class")
+public interface ResultReference {
+
+    OptimizationResult getResult() throws IOException;
+
+    Object getResultModel() throws IOException;
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/saving/ResultSaver.java

@@ -0,0 +1,57 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api.saving;
+
+import org.deeplearning4j.arbiter.optimize.api.OptimizationResult;
+import org.nd4j.shade.jackson.annotation.JsonInclude;
+import org.nd4j.shade.jackson.annotation.JsonTypeInfo;
+
+import java.io.IOException;
+import java.util.List;
+
+/**
+ * The ResultSaver interface provides a means of saving models in such a way that they can be loaded back into memory later,
+ * regardless of where/how they are saved.
+ *
+ * @author Alex Black
+ */
+@JsonInclude(JsonInclude.Include.NON_NULL)
+@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@class")
+public interface ResultSaver {
+
+    /**
+     * Save the model (including configuration and any additional evaluation/results)
+     *
+     * @param result        Optimization result for the model to save
+     * @param modelResult   Model result to save
+     * @return ResultReference, such that the result can be loaded back into memory
+     * @throws IOException If IO error occurs during model saving
+     */
+    ResultReference saveModel(OptimizationResult result, Object modelResult) throws IOException;
+
+    /**
+     * @return The candidate types supported by this class
+     */
+    List<Class<?>> getSupportedCandidateTypes();
+
+    /**
+     * @return The model types supported by this class
+     */
+    List<Class<?>> getSupportedModelTypes();
+
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/score/ScoreFunction.java

@@ -0,0 +1,75 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api.score;
+
+import org.deeplearning4j.arbiter.optimize.api.data.DataProvider;
+import org.deeplearning4j.arbiter.optimize.api.data.DataSource;
+import org.nd4j.shade.jackson.annotation.JsonInclude;
+import org.nd4j.shade.jackson.annotation.JsonTypeInfo;
+
+import java.io.Serializable;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+
+/**
+ * ScoreFunction defines the objective of hyperparameter optimization.
+ * Specifically, it is used to calculate a score for a given model, relative to the data set provided
+ * in the configuration.
+ *
+ */
+@JsonInclude(JsonInclude.Include.NON_NULL)
+@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@class")
+public interface ScoreFunction extends Serializable {
+
+    /**
+     * Calculate and return the score, for the given model and data provider
+     *
+     * @param model          Model to score
+     * @param dataProvider   Data provider - data to use
+     * @param dataParameters Parameters for data
+     * @return Calculated score
+     */
+    double score(Object model, DataProvider dataProvider, Map<String, Object> dataParameters);
+
+    /**
+     * Calculate and return the score, for the given model and data provider
+     *
+     * @param model                Model to score
+     * @param dataSource           Data source
+     * @param dataSourceProperties data source properties
+     * @return Calculated score
+     */
+    double score(Object model, Class<? extends DataSource> dataSource, Properties dataSourceProperties);
+
+    /**
+     * Should this score function be minimized or maximized?
+     *
+     * @return true if score should be minimized, false if score should be maximized
+     */
+    boolean minimize();
+
+    /**
+     * @return The model types supported by this class
+     */
+    List<Class<?>> getSupportedModelTypes();
+
+    /**
+     * @return The data types supported by this class
+     */
+    List<Class<?>> getSupportedDataTypes();
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/termination/MaxCandidatesCondition.java

@@ -0,0 +1,50 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api.termination;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.deeplearning4j.arbiter.optimize.runner.IOptimizationRunner;
+import org.nd4j.shade.jackson.annotation.JsonProperty;
+
+/**
+ * Terminate hyperparameter search when the number of candidates exceeds a specified value.
+ * Note that this is counted as number of completed candidates, plus number of failed candidates.
+ */
+@AllArgsConstructor
+@NoArgsConstructor
+@Data
+public class MaxCandidatesCondition implements TerminationCondition {
+    @JsonProperty
+    private int maxCandidates;
+
+    @Override
+    public void initialize(IOptimizationRunner optimizationRunner) {
+        //No op
+    }
+
+    @Override
+    public boolean terminate(IOptimizationRunner optimizationRunner) {
+        return optimizationRunner.numCandidatesCompleted() + optimizationRunner.numCandidatesFailed() >= maxCandidates;
+    }
+
+    @Override
+    public String toString() {
+        return "MaxCandidatesCondition(" + maxCandidates + ")";
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/termination/MaxTimeCondition.java

@@ -0,0 +1,81 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api.termination;
+
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.deeplearning4j.arbiter.optimize.runner.IOptimizationRunner;
+import org.joda.time.format.DateTimeFormat;
+import org.joda.time.format.DateTimeFormatter;
+import org.nd4j.shade.jackson.annotation.JsonProperty;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Terminate hyperparameter optimization after
+ * a fixed amount of time has passed
+ * @author Alex Black
+ */
+@NoArgsConstructor
+@Data
+public class MaxTimeCondition implements TerminationCondition {
+    private static final DateTimeFormatter formatter = DateTimeFormat.forPattern("dd-MMM HH:mm ZZ");
+
+    private long duration;
+    private TimeUnit timeUnit;
+    private long startTime;
+    private long endTime;
+
+
+    private MaxTimeCondition(@JsonProperty("duration") long duration, @JsonProperty("timeUnit") TimeUnit timeUnit,
+                    @JsonProperty("startTime") long startTime, @JsonProperty("endTime") long endTime) {
+        this.duration = duration;
+        this.timeUnit = timeUnit;
+        this.startTime = startTime;
+        this.endTime = endTime;
+    }
+
+    /**
+     * @param duration Duration of time
+     * @param timeUnit Unit that the duration is specified in
+     */
+    public MaxTimeCondition(long duration, TimeUnit timeUnit) {
+        this.duration = duration;
+        this.timeUnit = timeUnit;
+    }
+
+    @Override
+    public void initialize(IOptimizationRunner optimizationRunner) {
+        startTime = System.currentTimeMillis();
+        this.endTime = startTime + timeUnit.toMillis(duration);
+    }
+
+    @Override
+    public boolean terminate(IOptimizationRunner optimizationRunner) {
+        return System.currentTimeMillis() >= endTime;
+    }
+
+    @Override
+    public String toString() {
+        if (startTime > 0) {
+            return "MaxTimeCondition(" + duration + "," + timeUnit + ",start=\"" + formatter.print(startTime)
+                            + "\",end=\"" + formatter.print(endTime) + "\")";
+        } else {
+            return "MaxTimeCondition(" + duration + "," + timeUnit + "\")";
+        }
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/api/termination/TerminationCondition.java

@@ -0,0 +1,45 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.api.termination;
+
+
+import org.deeplearning4j.arbiter.optimize.runner.IOptimizationRunner;
+import org.nd4j.shade.jackson.annotation.JsonInclude;
+import org.nd4j.shade.jackson.annotation.JsonTypeInfo;
+
+/**
+ * Global termination condition for conducting hyperparameter optimization.
+ * Termination conditions are used to determine if/when the optimization should stop.
+ */
+@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@class")
+@JsonInclude(JsonInclude.Include.NON_NULL)
+public interface TerminationCondition {
+
+    /**
+     * Initialize the termination condition (such as starting timers, etc).
+     */
+    void initialize(IOptimizationRunner optimizationRunner);
+
+    /**
+     * Determine whether optimization should be terminated
+     *
+     * @param optimizationRunner Optimization runner
+     * @return true if learning should be terminated, false otherwise
+     */
+    boolean terminate(IOptimizationRunner optimizationRunner);
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/config/OptimizationConfiguration.java

@@ -0,0 +1,222 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.config;
+
+import lombok.*;
+import org.deeplearning4j.arbiter.optimize.api.CandidateGenerator;
+import org.deeplearning4j.arbiter.optimize.api.data.DataProvider;
+import org.deeplearning4j.arbiter.optimize.api.data.DataSource;
+import org.deeplearning4j.arbiter.optimize.api.saving.ResultSaver;
+import org.deeplearning4j.arbiter.optimize.api.score.ScoreFunction;
+import org.deeplearning4j.arbiter.optimize.api.termination.TerminationCondition;
+import org.deeplearning4j.arbiter.optimize.serde.jackson.JsonMapper;
+import org.nd4j.shade.jackson.annotation.JsonTypeInfo;
+import org.nd4j.shade.jackson.core.JsonProcessingException;
+import org.nd4j.shade.jackson.databind.annotation.JsonSerialize;
+
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Properties;
+
+/**
+ * OptimizationConfiguration ties together all of the various
+ * components (such as data, score functions, result saving etc)
+ * required to execute hyperparameter optimization.
+ *
+ * @author Alex Black
+ */
+@Data
+@NoArgsConstructor
+@EqualsAndHashCode(exclude = {"dataProvider", "terminationConditions", "candidateGenerator", "resultSaver"})
+@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@class")
+public class OptimizationConfiguration {
+    @JsonSerialize
+    private DataProvider dataProvider;
+    @JsonSerialize
+    private Class<? extends DataSource> dataSource;
+    @JsonSerialize
+    private Properties dataSourceProperties;
+    @JsonSerialize
+    private CandidateGenerator candidateGenerator;
+    @JsonSerialize
+    private ResultSaver resultSaver;
+    @JsonSerialize
+    private ScoreFunction scoreFunction;
+    @JsonSerialize
+    private List<TerminationCondition> terminationConditions;
+    @JsonSerialize
+    private Long rngSeed;
+
+    @Getter
+    @Setter
+    private long executionStartTime;
+
+
+    private OptimizationConfiguration(Builder builder) {
+        this.dataProvider = builder.dataProvider;
+        this.dataSource = builder.dataSource;
+        this.dataSourceProperties = builder.dataSourceProperties;
+        this.candidateGenerator = builder.candidateGenerator;
+        this.resultSaver = builder.resultSaver;
+        this.scoreFunction = builder.scoreFunction;
+        this.terminationConditions = builder.terminationConditions;
+        this.rngSeed = builder.rngSeed;
+
+        if (rngSeed != null)
+            candidateGenerator.setRngSeed(rngSeed);
+
+        //Validate the configuration: data types, score types, etc
+        //TODO
+
+        //Validate that the dataSource has a no-arg constructor
+        if(dataSource != null){
+            try{
+                dataSource.getConstructor();
+            } catch (NoSuchMethodException e){
+                throw new IllegalStateException("Data source class " + dataSource.getName() + " does not have a public no-argument constructor");
+            }
+        }
+    }
+
+    public static class Builder {
+
+        private DataProvider dataProvider;
+        private Class<? extends DataSource> dataSource;
+        private Properties dataSourceProperties;
+        private CandidateGenerator candidateGenerator;
+        private ResultSaver resultSaver;
+        private ScoreFunction scoreFunction;
+        private List<TerminationCondition> terminationConditions;
+        private Long rngSeed;
+
+        /**
+         * @deprecated Use {@link #dataSource(Class, Properties)}
+         */
+        @Deprecated
+        public Builder dataProvider(DataProvider dataProvider) {
+            this.dataProvider = dataProvider;
+            return this;
+        }
+
+        /**
+         * DataSource: defines where the data should come from for training and testing.
+         * Note that implementations must have a no-argument contsructor
+         * @param dataSource           Class for the data source
+         * @param dataSourceProperties May be null. Properties for configuring the data source
+         */
+        public Builder dataSource(Class<? extends DataSource> dataSource, Properties dataSourceProperties){
+            this.dataSource = dataSource;
+            this.dataSourceProperties = dataSourceProperties;
+            return this;
+        }
+
+        public Builder candidateGenerator(CandidateGenerator candidateGenerator) {
+            this.candidateGenerator = candidateGenerator;
+            return this;
+        }
+
+        public Builder modelSaver(ResultSaver resultSaver) {
+            this.resultSaver = resultSaver;
+            return this;
+        }
+
+        public Builder scoreFunction(ScoreFunction scoreFunction) {
+            this.scoreFunction = scoreFunction;
+            return this;
+        }
+
+        /**
+         * Termination conditions to use
+         * @param conditions
+         * @return
+         */
+        public Builder terminationConditions(TerminationCondition... conditions) {
+            terminationConditions = Arrays.asList(conditions);
+            return this;
+        }
+
+        public Builder terminationConditions(List<TerminationCondition> terminationConditions) {
+            this.terminationConditions = terminationConditions;
+            return this;
+        }
+
+        public Builder rngSeed(long rngSeed) {
+            this.rngSeed = rngSeed;
+            return this;
+        }
+
+        public OptimizationConfiguration build() {
+            return new OptimizationConfiguration(this);
+        }
+    }
+
+
+    /**
+     * Create an optimization configuration from the json
+     * @param json the json to create the config from
+     *  For type definitions
+     *  @see OptimizationConfiguration
+     */
+    public static OptimizationConfiguration fromYaml(String json) {
+        try {
+            return JsonMapper.getYamlMapper().readValue(json, OptimizationConfiguration.class);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    /**
+     * Create an optimization configuration from the json
+     * @param json the json to create the config from
+     *  @see OptimizationConfiguration
+     */
+    public static OptimizationConfiguration fromJson(String json) {
+        try {
+            return JsonMapper.getMapper().readValue(json, OptimizationConfiguration.class);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    /**
+     * Return a json configuration of this optimization configuration
+     *
+     * @return
+     */
+    public String toJson() {
+        try {
+            return JsonMapper.getMapper().writeValueAsString(this);
+        } catch (JsonProcessingException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    /**
+     * Return a yaml configuration of this optimization configuration
+     *
+     * @return
+     */
+    public String toYaml() {
+        try {
+            return JsonMapper.getYamlMapper().writeValueAsString(this);
+        } catch (JsonProcessingException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/distribution/DegenerateIntegerDistribution.java

@@ -0,0 +1,96 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.distribution;
+
+import org.apache.commons.math3.distribution.IntegerDistribution;
+import org.apache.commons.math3.exception.NumberIsTooLargeException;
+import org.apache.commons.math3.exception.OutOfRangeException;
+
+/**
+ * Degenerate distribution: i.e., integer "distribution" that is just a fixed value
+ */
+public class DegenerateIntegerDistribution implements IntegerDistribution {
+    private int value;
+
+    public DegenerateIntegerDistribution(int value) {
+        this.value = value;
+    }
+
+
+    @Override
+    public double probability(int x) {
+        return (x == value ? 1.0 : 0.0);
+    }
+
+    @Override
+    public double cumulativeProbability(int x) {
+        return (x >= value ? 1.0 : 0.0);
+    }
+
+    @Override
+    public double cumulativeProbability(int x0, int x1) throws NumberIsTooLargeException {
+        return (value >= x0 && value <= x1 ? 1.0 : 0.0);
+    }
+
+    @Override
+    public int inverseCumulativeProbability(double p) throws OutOfRangeException {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public double getNumericalMean() {
+        return value;
+    }
+
+    @Override
+    public double getNumericalVariance() {
+        return 0;
+    }
+
+    @Override
+    public int getSupportLowerBound() {
+        return value;
+    }
+
+    @Override
+    public int getSupportUpperBound() {
+        return value;
+    }
+
+    @Override
+    public boolean isSupportConnected() {
+        return true;
+    }
+
+    @Override
+    public void reseedRandomGenerator(long seed) {
+        //no op
+    }
+
+    @Override
+    public int sample() {
+        return value;
+    }
+
+    @Override
+    public int[] sample(int sampleSize) {
+        int[] out = new int[sampleSize];
+        for (int i = 0; i < out.length; i++)
+            out[i] = value;
+        return out;
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/distribution/DistributionUtils.java

@@ -0,0 +1,149 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.distribution;
+
+import org.apache.commons.math3.distribution.*;
+
+/**
+ * Distribution utils for Apache Commons math distributions - which don't provide equals, hashcode, toString methods,
+ * don't implement serializable etc.
+ * Which makes unit testing etc quite difficult.
+ *
+ * @author Alex Black
+ */
+public class DistributionUtils {
+
+    private DistributionUtils() {}
+
+
+    public static boolean distributionsEqual(RealDistribution a, RealDistribution b) {
+        if (a.getClass() != b.getClass())
+            return false;
+        Class<?> c = a.getClass();
+        if (c == BetaDistribution.class) {
+            BetaDistribution ba = (BetaDistribution) a;
+            BetaDistribution bb = (BetaDistribution) b;
+
+            return ba.getAlpha() == bb.getAlpha() && ba.getBeta() == bb.getBeta();
+        } else if (c == CauchyDistribution.class) {
+            CauchyDistribution ca = (CauchyDistribution) a;
+            CauchyDistribution cb = (CauchyDistribution) b;
+            return ca.getMedian() == cb.getMedian() && ca.getScale() == cb.getScale();
+        } else if (c == ChiSquaredDistribution.class) {
+            ChiSquaredDistribution ca = (ChiSquaredDistribution) a;
+            ChiSquaredDistribution cb = (ChiSquaredDistribution) b;
+            return ca.getDegreesOfFreedom() == cb.getDegreesOfFreedom();
+        } else if (c == ExponentialDistribution.class) {
+            ExponentialDistribution ea = (ExponentialDistribution) a;
+            ExponentialDistribution eb = (ExponentialDistribution) b;
+            return ea.getMean() == eb.getMean();
+        } else if (c == FDistribution.class) {
+            FDistribution fa = (FDistribution) a;
+            FDistribution fb = (FDistribution) b;
+            return fa.getNumeratorDegreesOfFreedom() == fb.getNumeratorDegreesOfFreedom()
+                            && fa.getDenominatorDegreesOfFreedom() == fb.getDenominatorDegreesOfFreedom();
+        } else if (c == GammaDistribution.class) {
+            GammaDistribution ga = (GammaDistribution) a;
+            GammaDistribution gb = (GammaDistribution) b;
+            return ga.getShape() == gb.getShape() && ga.getScale() == gb.getScale();
+        } else if (c == LevyDistribution.class) {
+            LevyDistribution la = (LevyDistribution) a;
+            LevyDistribution lb = (LevyDistribution) b;
+            return la.getLocation() == lb.getLocation() && la.getScale() == lb.getScale();
+        } else if (c == LogNormalDistribution.class) {
+            LogNormalDistribution la = (LogNormalDistribution) a;
+            LogNormalDistribution lb = (LogNormalDistribution) b;
+            return la.getScale() == lb.getScale() && la.getShape() == lb.getShape();
+        } else if (c == NormalDistribution.class) {
+            NormalDistribution na = (NormalDistribution) a;
+            NormalDistribution nb = (NormalDistribution) b;
+            return na.getMean() == nb.getMean() && na.getStandardDeviation() == nb.getStandardDeviation();
+        } else if (c == ParetoDistribution.class) {
+            ParetoDistribution pa = (ParetoDistribution) a;
+            ParetoDistribution pb = (ParetoDistribution) b;
+            return pa.getScale() == pb.getScale() && pa.getShape() == pb.getShape();
+        } else if (c == TDistribution.class) {
+            TDistribution ta = (TDistribution) a;
+            TDistribution tb = (TDistribution) b;
+            return ta.getDegreesOfFreedom() == tb.getDegreesOfFreedom();
+        } else if (c == TriangularDistribution.class) {
+            TriangularDistribution ta = (TriangularDistribution) a;
+            TriangularDistribution tb = (TriangularDistribution) b;
+            return ta.getSupportLowerBound() == tb.getSupportLowerBound()
+                            && ta.getSupportUpperBound() == tb.getSupportUpperBound() && ta.getMode() == tb.getMode();
+        } else if (c == UniformRealDistribution.class) {
+            UniformRealDistribution ua = (UniformRealDistribution) a;
+            UniformRealDistribution ub = (UniformRealDistribution) b;
+            return ua.getSupportLowerBound() == ub.getSupportLowerBound()
+                            && ua.getSupportUpperBound() == ub.getSupportUpperBound();
+        } else if (c == WeibullDistribution.class) {
+            WeibullDistribution wa = (WeibullDistribution) a;
+            WeibullDistribution wb = (WeibullDistribution) b;
+            return wa.getShape() == wb.getShape() && wa.getScale() == wb.getScale();
+        } else if (c == LogUniformDistribution.class ){
+            LogUniformDistribution lu_a = (LogUniformDistribution)a;
+            LogUniformDistribution lu_b = (LogUniformDistribution)b;
+            return lu_a.getMin() == lu_b.getMin() && lu_a.getMax() == lu_b.getMax();
+        } else {
+            throw new UnsupportedOperationException("Unknown or not supported RealDistribution: " + c);
+        }
+    }
+
+    public static boolean distributionEquals(IntegerDistribution a, IntegerDistribution b) {
+        if (a.getClass() != b.getClass())
+            return false;
+        Class<?> c = a.getClass();
+
+        if (c == BinomialDistribution.class) {
+            BinomialDistribution ba = (BinomialDistribution) a;
+            BinomialDistribution bb = (BinomialDistribution) b;
+            return ba.getNumberOfTrials() == bb.getNumberOfTrials()
+                            && ba.getProbabilityOfSuccess() == bb.getProbabilityOfSuccess();
+        } else if (c == GeometricDistribution.class) {
+            GeometricDistribution ga = (GeometricDistribution) a;
+            GeometricDistribution gb = (GeometricDistribution) b;
+            return ga.getProbabilityOfSuccess() == gb.getProbabilityOfSuccess();
+        } else if (c == HypergeometricDistribution.class) {
+            HypergeometricDistribution ha = (HypergeometricDistribution) a;
+            HypergeometricDistribution hb = (HypergeometricDistribution) b;
+            return ha.getPopulationSize() == hb.getPopulationSize()
+                            && ha.getNumberOfSuccesses() == hb.getNumberOfSuccesses()
+                            && ha.getSampleSize() == hb.getSampleSize();
+        } else if (c == PascalDistribution.class) {
+            PascalDistribution pa = (PascalDistribution) a;
+            PascalDistribution pb = (PascalDistribution) b;
+            return pa.getNumberOfSuccesses() == pb.getNumberOfSuccesses()
+                            && pa.getProbabilityOfSuccess() == pb.getProbabilityOfSuccess();
+        } else if (c == PoissonDistribution.class) {
+            PoissonDistribution pa = (PoissonDistribution) a;
+            PoissonDistribution pb = (PoissonDistribution) b;
+            return pa.getMean() == pb.getMean();
+        } else if (c == UniformIntegerDistribution.class) {
+            UniformIntegerDistribution ua = (UniformIntegerDistribution) a;
+            UniformIntegerDistribution ub = (UniformIntegerDistribution) b;
+            return ua.getSupportUpperBound() == ub.getSupportUpperBound()
+                            && ua.getSupportUpperBound() == ub.getSupportUpperBound();
+        } else if (c == ZipfDistribution.class) {
+            ZipfDistribution za = (ZipfDistribution) a;
+            ZipfDistribution zb = (ZipfDistribution) b;
+            return za.getNumberOfElements() == zb.getNumberOfElements() && za.getExponent() == zb.getNumberOfElements();
+        } else {
+            throw new UnsupportedOperationException("Unknown or not supported IntegerDistribution: " + c);
+        }
+
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/distribution/LogUniformDistribution.java

@@ -0,0 +1,155 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.distribution;
+
+import com.google.common.base.Preconditions;
+import lombok.Getter;
+import org.apache.commons.math3.distribution.RealDistribution;
+import org.apache.commons.math3.exception.NumberIsTooLargeException;
+import org.apache.commons.math3.exception.OutOfRangeException;
+
+import java.util.Random;
+
+/**
+ * Log uniform distribution, with support in range [min, max] for min > 0
+ *
+ * Reference: <a href="https://www.vosesoftware.com/riskwiki/LogUniformdistribution.php">https://www.vosesoftware.com/riskwiki/LogUniformdistribution.php</a>
+ *
+ * @author Alex Black
+ */
+public class LogUniformDistribution implements RealDistribution {
+
+    @Getter private final double min;
+    @Getter private final double max;
+
+    private final double logMin;
+    private final double logMax;
+
+    private transient Random rng = new Random();
+
+    /**
+     *
+     * @param min Minimum value
+     * @param max Maximum value
+     */
+    public LogUniformDistribution(double min, double max) {
+        Preconditions.checkArgument(min > 0, "Minimum must be > 0. Got: " + min);
+        Preconditions.checkArgument(max > min, "Maximum must be > min. Got: (min, max)=("
+                + min + "," + max + ")");
+        this.min = min;
+        this.max = max;
+
+        this.logMin = Math.log(min);
+        this.logMax = Math.log(max);
+    }
+
+    @Override
+    public double probability(double x) {
+        if(x < min || x > max){
+            return 0;
+        }
+
+        return 1.0 / (x * (logMax - logMin));
+    }
+
+    @Override
+    public double density(double x) {
+        return probability(x);
+    }
+
+    @Override
+    public double cumulativeProbability(double x) {
+        if(x <= min){
+            return 0.0;
+        } else if(x >= max){
+            return 1.0;
+        }
+
+        return (Math.log(x)-logMin)/(logMax-logMin);
+    }
+
+    @Override
+    public double cumulativeProbability(double x0, double x1) throws NumberIsTooLargeException {
+        return cumulativeProbability(x1) - cumulativeProbability(x0);
+    }
+
+    @Override
+    public double inverseCumulativeProbability(double p) throws OutOfRangeException {
+        Preconditions.checkArgument(p >= 0 && p <= 1, "Invalid input: " + p);
+        return Math.exp(p * (logMax-logMin) + logMin);
+    }
+
+    @Override
+    public double getNumericalMean() {
+        return (max-min)/(logMax-logMin);
+    }
+
+    @Override
+    public double getNumericalVariance() {
+        double d1 = (logMax-logMin)*(max*max - min*min) - 2*(max-min)*(max-min);
+        return d1 / (2*Math.pow(logMax-logMin, 2.0));
+    }
+
+    @Override
+    public double getSupportLowerBound() {
+        return min;
+    }
+
+    @Override
+    public double getSupportUpperBound() {
+        return max;
+    }
+
+    @Override
+    public boolean isSupportLowerBoundInclusive() {
+        return true;
+    }
+
+    @Override
+    public boolean isSupportUpperBoundInclusive() {
+        return true;
+    }
+
+    @Override
+    public boolean isSupportConnected() {
+        return true;
+    }
+
+    @Override
+    public void reseedRandomGenerator(long seed) {
+        rng.setSeed(seed);
+    }
+
+    @Override
+    public double sample() {
+        return inverseCumulativeProbability(rng.nextDouble());
+    }
+
+    @Override
+    public double[] sample(int sampleSize) {
+        double[] d = new double[sampleSize];
+        for( int i=0; i<sampleSize; i++ ){
+            d[i] = sample();
+        }
+        return d;
+    }
+
+    @Override
+    public String toString(){
+        return "LogUniformDistribution(min=" + min + ",max=" + max + ")";
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/BaseCandidateGenerator.java

@@ -0,0 +1,91 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator;
+
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import org.apache.commons.math3.random.JDKRandomGenerator;
+import org.apache.commons.math3.random.SynchronizedRandomGenerator;
+import org.deeplearning4j.arbiter.optimize.api.CandidateGenerator;
+import org.deeplearning4j.arbiter.optimize.api.OptimizationResult;
+import org.deeplearning4j.arbiter.optimize.api.ParameterSpace;
+import org.deeplearning4j.arbiter.util.LeafUtils;
+
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * BaseCandidateGenerator: abstract class upon which {@link RandomSearchGenerator}, 
+ * {@link GridSearchCandidateGenerator} and {@link GeneticSearchCandidateGenerator}
+ * are built.
+ *
+ * @param <T> Type of candidates to generate
+ */
+@Data
+@EqualsAndHashCode(exclude = {"rng", "candidateCounter"})
+public abstract class BaseCandidateGenerator<T> implements CandidateGenerator {
+    protected ParameterSpace<T> parameterSpace;
+    protected AtomicInteger candidateCounter = new AtomicInteger(0);
+    protected SynchronizedRandomGenerator rng = new SynchronizedRandomGenerator(new JDKRandomGenerator());
+    protected Map<String, Object> dataParameters;
+    protected boolean initDone = false;
+
+    public BaseCandidateGenerator(ParameterSpace<T> parameterSpace, Map<String, Object> dataParameters,
+                                  boolean initDone) {
+        this.parameterSpace = parameterSpace;
+        this.dataParameters = dataParameters;
+        this.initDone = initDone;
+    }
+
+    protected void initialize() {
+        if(!initDone) {
+            //First: collect leaf parameter spaces objects and remove duplicates
+            List<ParameterSpace> noDuplicatesList = LeafUtils.getUniqueObjects(parameterSpace.collectLeaves());
+
+            //Second: assign each a number
+            int i = 0;
+            for (ParameterSpace ps : noDuplicatesList) {
+                int np = ps.numParameters();
+                if (np == 1) {
+                    ps.setIndices(i++);
+                } else {
+                    int[] values = new int[np];
+                    for (int j = 0; j < np; j++)
+                        values[j] = i++;
+                    ps.setIndices(values);
+                }
+            }
+            initDone = true;
+        }
+    }
+
+    @Override
+    public ParameterSpace<T> getParameterSpace() {
+        return parameterSpace;
+    }
+
+    @Override
+    public void reportResults(OptimizationResult result) {
+        //No op
+    }
+
+    @Override
+    public void setRngSeed(long rngSeed) {
+        rng.setSeed(rngSeed);
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/GeneticSearchCandidateGenerator.java

@@ -0,0 +1,187 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator;
+
+import lombok.Getter;
+import lombok.extern.slf4j.Slf4j;
+import org.deeplearning4j.arbiter.optimize.api.Candidate;
+import org.deeplearning4j.arbiter.optimize.api.OptimizationResult;
+import org.deeplearning4j.arbiter.optimize.api.ParameterSpace;
+import org.deeplearning4j.arbiter.optimize.api.score.ScoreFunction;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.Chromosome;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.ChromosomeFactory;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.exceptions.GeneticGenerationException;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.population.EmptyPopulationInitializer;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.population.PopulationInitializer;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.population.PopulationModel;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.selection.GeneticSelectionOperator;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.selection.SelectionOperator;
+
+import java.util.Map;
+
+/**
+ * Uses a genetic algorithm to generate candidates.
+ *
+ * @author Alexandre Boulanger
+ */
+@Slf4j
+public class GeneticSearchCandidateGenerator extends BaseCandidateGenerator {
+
+    @Getter
+    protected final PopulationModel populationModel;
+
+    protected final ChromosomeFactory chromosomeFactory;
+    protected final SelectionOperator selectionOperator;
+
+    protected boolean hasMoreCandidates = true;
+
+    public static class Builder {
+        protected final ParameterSpace<?> parameterSpace;
+
+        protected Map<String, Object> dataParameters;
+        protected boolean initDone;
+        protected boolean minimizeScore;
+        protected PopulationModel populationModel;
+        protected ChromosomeFactory chromosomeFactory;
+        protected SelectionOperator selectionOperator;
+
+        /**
+         * @param parameterSpace ParameterSpace from which to generate candidates
+         * @param scoreFunction The score function that will be used in the OptimizationConfiguration
+         */
+        public Builder(ParameterSpace<?> parameterSpace, ScoreFunction scoreFunction) {
+            this.parameterSpace = parameterSpace;
+            this.minimizeScore = scoreFunction.minimize();
+        }
+
+        /**
+         * @param populationModel The PopulationModel instance to use.
+         */
+        public Builder populationModel(PopulationModel populationModel) {
+            this.populationModel = populationModel;
+            return this;
+        }
+
+        /**
+         * @param selectionOperator The SelectionOperator to use. Default is GeneticSelectionOperator
+         */
+        public Builder selectionOperator(SelectionOperator selectionOperator) {
+            this.selectionOperator = selectionOperator;
+            return this;
+        }
+
+        public Builder dataParameters(Map<String, Object> dataParameters) {
+
+            this.dataParameters = dataParameters;
+            return this;
+        }
+
+        public GeneticSearchCandidateGenerator.Builder initDone(boolean initDone) {
+            this.initDone = initDone;
+            return this;
+        }
+
+        /**
+         * @param chromosomeFactory The ChromosomeFactory to use
+         */
+        public Builder chromosomeFactory(ChromosomeFactory chromosomeFactory) {
+            this.chromosomeFactory = chromosomeFactory;
+            return this;
+        }
+
+        public GeneticSearchCandidateGenerator build() {
+            if (populationModel == null) {
+                PopulationInitializer defaultPopulationInitializer = new EmptyPopulationInitializer();
+                populationModel = new PopulationModel.Builder().populationInitializer(defaultPopulationInitializer)
+                                .build();
+            }
+
+            if (chromosomeFactory == null) {
+                chromosomeFactory = new ChromosomeFactory();
+            }
+
+            if (selectionOperator == null) {
+                selectionOperator = new GeneticSelectionOperator.Builder().build();
+            }
+
+            return new GeneticSearchCandidateGenerator(this);
+        }
+    }
+
+    private GeneticSearchCandidateGenerator(Builder builder) {
+        super(builder.parameterSpace, builder.dataParameters, builder.initDone);
+
+        initialize();
+
+        chromosomeFactory = builder.chromosomeFactory;
+        populationModel = builder.populationModel;
+        selectionOperator = builder.selectionOperator;
+
+        chromosomeFactory.initializeInstance(builder.parameterSpace.numParameters());
+        populationModel.initializeInstance(builder.minimizeScore);
+        selectionOperator.initializeInstance(populationModel, chromosomeFactory);
+
+    }
+
+    @Override
+    public boolean hasMoreCandidates() {
+        return hasMoreCandidates;
+    }
+
+    @Override
+    public Candidate getCandidate() {
+
+        double[] values = null;
+        Object value = null;
+        Exception e = null;
+
+        try {
+            values = selectionOperator.buildNextGenes();
+            value = parameterSpace.getValue(values);
+        } catch (GeneticGenerationException e2) {
+            log.warn("Error generating candidate", e2);
+            e = e2;
+            hasMoreCandidates = false;
+        } catch (Exception e2) {
+            log.warn("Error getting configuration for candidate", e2);
+            e = e2;
+        }
+
+        return new Candidate(value, candidateCounter.getAndIncrement(), values, dataParameters, e);
+    }
+
+    @Override
+    public Class<?> getCandidateType() {
+        return null;
+    }
+
+    @Override
+    public String toString() {
+        return "GeneticSearchCandidateGenerator";
+    }
+
+    @Override
+    public void reportResults(OptimizationResult result) {
+        if (result.getScore() == null) {
+            return;
+        }
+
+        Chromosome newChromosome = chromosomeFactory.createChromosome(result.getCandidate().getFlatParameters(),
+                        result.getScore());
+        populationModel.add(newChromosome);
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/GridSearchCandidateGenerator.java

@@ -0,0 +1,223 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator;
+
+import lombok.EqualsAndHashCode;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.commons.math3.random.RandomAdaptor;
+import org.deeplearning4j.arbiter.optimize.api.Candidate;
+import org.deeplearning4j.arbiter.optimize.api.ParameterSpace;
+import org.deeplearning4j.arbiter.optimize.parameter.discrete.DiscreteParameterSpace;
+import org.deeplearning4j.arbiter.optimize.parameter.integer.IntegerParameterSpace;
+import org.deeplearning4j.arbiter.util.LeafUtils;
+import org.nd4j.shade.jackson.annotation.JsonIgnoreProperties;
+import org.nd4j.shade.jackson.annotation.JsonProperty;
+
+import java.util.*;
+import java.util.concurrent.ConcurrentLinkedQueue;
+
+
+/**
+ * GridSearchCandidateGenerator: generates candidates in an exhaustive grid search manner.<br>
+ * Note that:<br>
+ * - For discrete parameters: the grid size (# values to check per hyperparameter) is equal to the number of values for
+ * that hyperparameter<br>
+ * - For integer parameters: the grid size is equal to {@code min(discretizationCount,max-min+1)}. Some integer ranges can
+ * be large, and we don't necessarily want to exhaustively search them. {@code discretizationCount} is a constructor argument<br>
+ * - For continuous parameters: the grid size is equal to {@code discretizationCount}.<br>
+ * In all cases, the minimum, maximum and gridSize-2 values between the min/max will be generated.<br>
+ * Also note that: if a probability distribution is provided for continuous hyperparameters, this will be taken into account
+ * when generating candidates. This allows the grid for a hyperparameter to be non-linear: i.e., for example, linear in log space
+ *
+ * @author Alex Black
+ */
+@Slf4j
+@EqualsAndHashCode(exclude = {"order"}, callSuper = true)
+@JsonIgnoreProperties({"numValuesPerParam", "totalNumCandidates", "order", "candidateCounter", "rng", "candidate"})
+public class GridSearchCandidateGenerator extends BaseCandidateGenerator {
+
+    /**
+     * In what order should candidates be generated?<br>
+     * <b>Sequential</b>: generate candidates in order. The first hyperparameter will be changed most rapidly, and the last
+     * will be changed least rapidly.<br>
+     * <b>RandomOrder</b>: generate candidates in a random order<br>
+     * In both cases, the same candidates will be generated; only the order of generation is different
+     */
+    public enum Mode {
+        Sequential, RandomOrder
+    }
+
+    private final int discretizationCount;
+    private final Mode mode;
+
+    private int[] numValuesPerParam;
+    private int totalNumCandidates;
+    private Queue<Integer> order;
+
+    /**
+     * @param parameterSpace      ParameterSpace from which to generate candidates
+     * @param discretizationCount For continuous parameters: into how many values should we discretize them into?
+     *                            For example, suppose continuous parameter is in range [0,1] with 3 bins:
+     *                            do [0.0, 0.5, 1.0]. Note that if all values
+     * @param mode                {@link GridSearchCandidateGenerator.Mode} specifies the order
+     *                            in which candidates should be generated.
+     */
+    public GridSearchCandidateGenerator(@JsonProperty("parameterSpace") ParameterSpace<?> parameterSpace,
+                    @JsonProperty("discretizationCount") int discretizationCount, @JsonProperty("mode") Mode mode,
+                    @JsonProperty("dataParameters") Map<String, Object> dataParameters,
+                    @JsonProperty("initDone") boolean initDone) {
+        super(parameterSpace, dataParameters, initDone);
+        this.discretizationCount = discretizationCount;
+        this.mode = mode;
+        initialize();
+    }
+
+    /**
+     * @param parameterSpace      ParameterSpace from which to generate candidates
+     * @param discretizationCount For continuous parameters: into how many values should we discretize them into?
+     *                            For example, suppose continuous parameter is in range [0,1] with 3 bins:
+     *                            do [0.0, 0.5, 1.0]. Note that if all values
+     * @param mode                {@link GridSearchCandidateGenerator.Mode} specifies the order
+     *                            in which candidates should be generated.
+     */
+    public GridSearchCandidateGenerator(ParameterSpace<?> parameterSpace, int discretizationCount, Mode mode,
+                                        Map<String, Object> dataParameters){
+        this(parameterSpace, discretizationCount, mode, dataParameters, false);
+    }
+
+    @Override
+    protected void initialize() {
+        super.initialize();
+
+        List<ParameterSpace> leaves = LeafUtils.getUniqueObjects(parameterSpace.collectLeaves());
+        int nParams = leaves.size();
+
+        //Work out for each parameter: is it continuous or discrete?
+        // for grid search: discrete values are grid-searchable as-is
+        // continuous values: discretize using 'discretizationCount' bins
+        // integer values: use min(max-min+1, discretizationCount) values. i.e., discretize if necessary
+        numValuesPerParam = new int[nParams];
+        long searchSize = 1;
+        for (int i = 0; i < nParams; i++) {
+            ParameterSpace ps = leaves.get(i);
+            if (ps instanceof DiscreteParameterSpace) {
+                DiscreteParameterSpace dps = (DiscreteParameterSpace) ps;
+                numValuesPerParam[i] = dps.numValues();
+            } else if (ps instanceof IntegerParameterSpace) {
+                IntegerParameterSpace ips = (IntegerParameterSpace) ps;
+                int min = ips.getMin();
+                int max = ips.getMax();
+                //Discretize, as some integer ranges are much too large to search (i.e., num. neural network units, between 100 and 1000)
+                numValuesPerParam[i] = Math.min(max - min + 1, discretizationCount);
+            } else {
+                numValuesPerParam[i] = discretizationCount;
+            }
+            searchSize *= numValuesPerParam[i];
+        }
+
+        if (searchSize >= Integer.MAX_VALUE)
+            throw new IllegalStateException("Invalid search: cannot process search with " + searchSize
+                            + " candidates > Integer.MAX_VALUE"); //TODO find a more reasonable upper bound?
+
+        order = new ConcurrentLinkedQueue<>();
+
+        totalNumCandidates = (int) searchSize;
+        switch (mode) {
+            case Sequential:
+                for (int i = 0; i < totalNumCandidates; i++) {
+                    order.add(i);
+                }
+                break;
+            case RandomOrder:
+                List<Integer> tempList = new ArrayList<>(totalNumCandidates);
+                for (int i = 0; i < totalNumCandidates; i++) {
+                    tempList.add(i);
+                }
+
+                Collections.shuffle(tempList, new RandomAdaptor(rng));
+                order.addAll(tempList);
+                break;
+            default:
+                throw new RuntimeException();
+        }
+
+    }
+
+    @Override
+    public boolean hasMoreCandidates() {
+        return !order.isEmpty();
+    }
+
+    @Override
+    public Candidate getCandidate() {
+        int next = order.remove();
+
+        //Next: max integer (candidate number) to values
+        double[] values = indexToValues(numValuesPerParam, next, totalNumCandidates);
+
+        Object value = null;
+        Exception e = null;
+        try {
+            value = parameterSpace.getValue(values);
+        } catch (Exception e2) {
+            log.warn("Error getting configuration for candidate", e2);
+            e = e2;
+        }
+
+        return new Candidate(value, candidateCounter.getAndIncrement(), values, dataParameters, e);
+    }
+
+    @Override
+    public Class<?> getCandidateType() {
+        return null;
+    }
+
+    public static double[] indexToValues(int[] numValuesPerParam, int candidateIdx, int product) {
+        //How? first map to index of num possible values. Then: to double values in range 0 to 1
+        // 0-> [0,0,0], 1-> [1,0,0], 2-> [2,0,0], 3-> [0,1,0] etc
+        //Based on: Nd4j Shape.ind2sub
+
+        int denom = product;
+        int num = candidateIdx;
+        int[] index = new int[numValuesPerParam.length];
+
+        for (int i = index.length - 1; i >= 0; i--) {
+            denom /= numValuesPerParam[i];
+            index[i] = num / denom;
+            num %= denom;
+        }
+
+        //Now: convert indexes to values in range [0,1]
+        //min value -> 0
+        //max value -> 1
+        double[] out = new double[numValuesPerParam.length];
+        for (int i = 0; i < out.length; i++) {
+            if (numValuesPerParam[i] <= 1)
+                out[i] = 0.0;
+            else {
+                out[i] = index[i] / ((double) (numValuesPerParam[i] - 1));
+            }
+        }
+
+        return out;
+    }
+
+    @Override
+    public String toString() {
+        return "GridSearchCandidateGenerator(mode=" + mode + ")";
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/RandomSearchGenerator.java

@@ -0,0 +1,93 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator;
+
+import lombok.EqualsAndHashCode;
+import lombok.extern.slf4j.Slf4j;
+import org.deeplearning4j.arbiter.optimize.api.Candidate;
+import org.deeplearning4j.arbiter.optimize.api.ParameterSpace;
+import org.nd4j.shade.jackson.annotation.JsonCreator;
+import org.nd4j.shade.jackson.annotation.JsonIgnoreProperties;
+import org.nd4j.shade.jackson.annotation.JsonProperty;
+
+import java.util.Map;
+
+/**
+ * RandomSearchGenerator: generates candidates at random.<br>
+ * Note: if a probability distribution is provided for continuous hyperparameters,
+ * this will be taken into account
+ * when generating candidates. This allows the search to be weighted more towards
+ * certain values according to a probability
+ * density. For example: generate samples for learning rate according to log uniform distribution
+ *
+ * @author Alex Black
+ */
+@Slf4j
+@EqualsAndHashCode(callSuper = true)
+@JsonIgnoreProperties({"numValuesPerParam", "totalNumCandidates", "order", "candidateCounter", "rng", "candidate"})
+public class RandomSearchGenerator extends BaseCandidateGenerator {
+
+    @JsonCreator
+    public RandomSearchGenerator(@JsonProperty("parameterSpace") ParameterSpace<?> parameterSpace,
+                    @JsonProperty("dataParameters") Map<String, Object> dataParameters,
+                                 @JsonProperty("initDone") boolean initDone) {
+        super(parameterSpace, dataParameters, initDone);
+        initialize();
+    }
+
+    public RandomSearchGenerator(ParameterSpace<?> parameterSpace, Map<String,Object> dataParameters){
+        this(parameterSpace, dataParameters, false);
+    }
+
+    public RandomSearchGenerator(ParameterSpace<?> parameterSpace){
+        this(parameterSpace, null, false);
+    }
+
+
+    @Override
+    public boolean hasMoreCandidates() {
+        return true;
+    }
+
+    @Override
+    public Candidate getCandidate() {
+        double[] randomValues = new double[parameterSpace.numParameters()];
+        for (int i = 0; i < randomValues.length; i++)
+            randomValues[i] = rng.nextDouble();
+
+        Object value = null;
+        Exception e = null;
+        try {
+            value = parameterSpace.getValue(randomValues);
+        } catch (Exception e2) {
+            log.warn("Error getting configuration for candidate", e2);
+            e = e2;
+        }
+
+        return new Candidate(value, candidateCounter.getAndIncrement(), randomValues, dataParameters, e);
+    }
+
+    @Override
+    public Class<?> getCandidateType() {
+        return null;
+    }
+
+    @Override
+    public String toString() {
+        return "RandomSearchGenerator";
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/Chromosome.java

@@ -0,0 +1,42 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic;
+
+import lombok.Data;
+
+/**
+ * Candidates are stored as Chromosome in the population model
+ *
+ * @author Alexandre Boulanger
+ */
+@Data
+public class Chromosome {
+    /**
+     * The fitness score of the genes.
+     */
+    protected final double fitness;
+
+    /**
+     * The genes.
+     */
+    protected final double[] genes;
+
+    public Chromosome(double[] genes, double fitness) {
+        this.genes = genes;
+        this.fitness = fitness;
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/ChromosomeFactory.java

@@ -0,0 +1,51 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic;
+
+/**
+ * A factory that builds new chromosomes. Used by the GeneticSearchCandidateGenerator.
+ *
+ * @author Alexandre Boulanger
+ */
+public class ChromosomeFactory {
+    private int chromosomeLength;
+
+    /**
+     * Called by the GeneticSearchCandidateGenerator.
+     */
+    public void initializeInstance(int chromosomeLength) {
+        this.chromosomeLength = chromosomeLength;
+    }
+
+    /**
+     * Create a new instance of a Chromosome
+     *
+     * @param genes The genes
+     * @param fitness The fitness score
+     * @return A new instance of Chromosome
+     */
+    public Chromosome createChromosome(double[] genes, double fitness) {
+        return new Chromosome(genes, fitness);
+    }
+
+    /**
+     * @return The number of genes in a chromosome
+     */
+    public int getChromosomeLength() {
+        return chromosomeLength;
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/crossover/ArithmeticCrossover.java

@@ -0,0 +1,120 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.crossover;
+
+import org.apache.commons.math3.random.JDKRandomGenerator;
+import org.apache.commons.math3.random.RandomGenerator;
+import org.apache.commons.math3.random.SynchronizedRandomGenerator;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.parentselection.RandomTwoParentSelection;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.parentselection.TwoParentSelection;
+import org.nd4j.base.Preconditions;
+
+/**
+ * A crossover operator that linearly combines the genes of two parents. <br>
+ * When a crossover is generated (with a of probability <i>crossover rate</i>), each genes is a linear combination of the corresponding genes of the parents.
+ * <p>
+ * <i>t*parentA + (1-t)*parentB, where t is [0, 1] and different for each gene.</i>
+ * 
+ * @author Alexandre Boulanger
+ */
+public class ArithmeticCrossover extends TwoParentsCrossoverOperator {
+    private static final double DEFAULT_CROSSOVER_RATE = 0.85;
+
+    private final double crossoverRate;
+    private final RandomGenerator rng;
+
+    public static class Builder {
+        private double crossoverRate = DEFAULT_CROSSOVER_RATE;
+        private RandomGenerator rng;
+        private TwoParentSelection parentSelection;
+
+        /**
+         * The probability that the operator generates a crossover (default 0.85).
+         *
+         * @param rate A value between 0.0 and 1.0
+         */
+        public Builder crossoverRate(double rate) {
+            Preconditions.checkState(rate >= 0.0 && rate <= 1.0, "Rate must be between 0.0 and 1.0, got %s", rate);
+
+            this.crossoverRate = rate;
+            return this;
+        }
+
+        /**
+         * Use a supplied RandomGenerator
+         *
+         * @param rng An instance of RandomGenerator
+         */
+        public Builder randomGenerator(RandomGenerator rng) {
+            this.rng = rng;
+            return this;
+        }
+
+        /**
+         * The parent selection behavior. Default is random parent selection.
+         *
+         * @param parentSelection An instance of TwoParentSelection
+         */
+        public Builder parentSelection(TwoParentSelection parentSelection) {
+            this.parentSelection = parentSelection;
+            return this;
+        }
+
+        public ArithmeticCrossover build() {
+            if (rng == null) {
+                rng = new SynchronizedRandomGenerator(new JDKRandomGenerator());
+            }
+
+            if (parentSelection == null) {
+                parentSelection = new RandomTwoParentSelection();
+            }
+
+            return new ArithmeticCrossover(this);
+        }
+    }
+
+    private ArithmeticCrossover(ArithmeticCrossover.Builder builder) {
+        super(builder.parentSelection);
+
+        this.crossoverRate = builder.crossoverRate;
+        this.rng = builder.rng;
+    }
+
+    /**
+     * Has a probability <i>crossoverRate</i> of performing the crossover where each gene is a linear combination of:<br>
+     *     <i>t*parentA + (1-t)*parentB, where t is [0, 1] and different for each gene.</i><br>
+     * Otherwise, returns the genes of a random parent.
+     *
+     * @return The crossover result. See {@link CrossoverResult}.
+     */
+    @Override
+    public CrossoverResult crossover() {
+        double[][] parents = parentSelection.selectParents();
+
+        double[] offspringValues = new double[parents[0].length];
+
+        if (rng.nextDouble() < crossoverRate) {
+            for (int i = 0; i < offspringValues.length; ++i) {
+                double t = rng.nextDouble();
+                offspringValues[i] = t * parents[0][i] + (1.0 - t) * parents[1][i];
+            }
+            return new CrossoverResult(true, offspringValues);
+        }
+
+        return new CrossoverResult(false, parents[0]);
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/crossover/CrossoverOperator.java

@@ -0,0 +1,45 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.crossover;
+
+import org.deeplearning4j.arbiter.optimize.generator.genetic.population.PopulationModel;
+
+/**
+ * Abstract class for all crossover operators
+ * 
+ * @author Alexandre Boulanger
+ */
+public abstract class CrossoverOperator {
+    protected PopulationModel populationModel;
+
+    /**
+     * Will be called by the selection operator once the population model is instantiated.
+     */
+    public void initializeInstance(PopulationModel populationModel) {
+        this.populationModel = populationModel;
+    }
+
+    /**
+     * Performs the crossover
+     *
+     * @return The crossover result. See {@link CrossoverResult}.
+     */
+    public abstract CrossoverResult crossover();
+
+
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/crossover/CrossoverResult.java

@@ -0,0 +1,43 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.crossover;
+
+import lombok.Data;
+
+/**
+ * Returned by a crossover operator
+ * 
+ * @author Alexandre Boulanger
+ */
+@Data
+public class CrossoverResult {
+    /**
+    * If false, there was no crossover and the operator simply returned the genes of a random parent.
+    * If true, the genes are the result of a crossover.
+    */
+    private final boolean isModified;
+
+    /**
+    * The genes returned by the operator.
+    */
+    private final double[] genes;
+
+    public CrossoverResult(boolean isModified, double[] genes) {
+        this.isModified = isModified;
+        this.genes = genes;
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/crossover/KPointCrossover.java

@@ -0,0 +1,178 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.crossover;
+
+import org.apache.commons.math3.random.JDKRandomGenerator;
+import org.apache.commons.math3.random.RandomGenerator;
+import org.apache.commons.math3.random.SynchronizedRandomGenerator;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.parentselection.RandomTwoParentSelection;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.parentselection.TwoParentSelection;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.utils.CrossoverPointsGenerator;
+import org.nd4j.base.Preconditions;
+
+import java.util.Deque;
+
+/**
+* The K-Point crossover will select at random multiple crossover points.<br>
+* Each gene comes from one of the two parents. Each time a crossover point is reached, the parent is switched.
+*/
+public class KPointCrossover extends TwoParentsCrossoverOperator {
+    private static final double DEFAULT_CROSSOVER_RATE = 0.85;
+    private static final int DEFAULT_MIN_CROSSOVER = 1;
+    private static final int DEFAULT_MAX_CROSSOVER = 4;
+
+    private final double crossoverRate;
+    private final int minCrossovers;
+    private final int maxCrossovers;
+
+    private final RandomGenerator rng;
+
+    public static class Builder {
+        private double crossoverRate = DEFAULT_CROSSOVER_RATE;
+        private int minCrossovers = DEFAULT_MIN_CROSSOVER;
+        private int maxCrossovers = DEFAULT_MAX_CROSSOVER;
+        private RandomGenerator rng;
+        private TwoParentSelection parentSelection;
+
+        /**
+         * The probability that the operator generates a crossover (default 0.85).
+         *
+         * @param rate A value between 0.0 and 1.0
+         */
+        public Builder crossoverRate(double rate) {
+            Preconditions.checkState(rate >= 0.0 && rate <= 1.0, "Rate must be between 0.0 and 1.0, got %s", rate);
+
+            this.crossoverRate = rate;
+            return this;
+        }
+
+        /**
+         * The number of crossovers points (default is min 1, max 4)
+         *
+         * @param min The minimum number
+         * @param max The maximum number
+         */
+        public Builder numCrossovers(int min, int max) {
+            Preconditions.checkState(max >= 0 && min >= 0, "Min and max must be positive");
+            Preconditions.checkState(max >= min, "Max must be greater or equal to min");
+
+            this.minCrossovers = min;
+            this.maxCrossovers = max;
+            return this;
+        }
+
+        /**
+         * Use a fixed number of crossover points
+         *
+         * @param num The number of crossovers
+         */
+        public Builder numCrossovers(int num) {
+            Preconditions.checkState(num >= 0, "Num must be positive");
+
+            this.minCrossovers = num;
+            this.maxCrossovers = num;
+            return this;
+        }
+
+        /**
+         * Use a supplied RandomGenerator
+         *
+         * @param rng An instance of RandomGenerator
+         */
+        public Builder randomGenerator(RandomGenerator rng) {
+            this.rng = rng;
+            return this;
+        }
+
+        /**
+         * The parent selection behavior. Default is random parent selection.
+         *
+         * @param parentSelection An instance of TwoParentSelection
+         */
+        public Builder parentSelection(TwoParentSelection parentSelection) {
+            this.parentSelection = parentSelection;
+            return this;
+        }
+
+        public KPointCrossover build() {
+            if (rng == null) {
+                rng = new SynchronizedRandomGenerator(new JDKRandomGenerator());
+            }
+
+            if (parentSelection == null) {
+                parentSelection = new RandomTwoParentSelection();
+            }
+
+            return new KPointCrossover(this);
+        }
+    }
+
+    private CrossoverPointsGenerator crossoverPointsGenerator;
+
+    private KPointCrossover(KPointCrossover.Builder builder) {
+        super(builder.parentSelection);
+
+        this.crossoverRate = builder.crossoverRate;
+        this.maxCrossovers = builder.maxCrossovers;
+        this.minCrossovers = builder.minCrossovers;
+        this.rng = builder.rng;
+    }
+
+    private CrossoverPointsGenerator getCrossoverPointsGenerator(int chromosomeLength) {
+        if (crossoverPointsGenerator == null) {
+            crossoverPointsGenerator =
+                    new CrossoverPointsGenerator(chromosomeLength, minCrossovers, maxCrossovers, rng);
+        }
+
+        return crossoverPointsGenerator;
+    }
+
+    /**
+     * Has a probability <i>crossoverRate</i> of performing the crossover where the operator will select at random multiple crossover points.<br>
+     * Each gene comes from one of the two parents. Each time a crossover point is reached, the parent is switched. <br>
+     * Otherwise, returns the genes of a random parent.
+     *
+     * @return The crossover result. See {@link CrossoverResult}.
+     */
+    @Override
+    public CrossoverResult crossover() {
+        double[][] parents = parentSelection.selectParents();
+
+        boolean isModified = false;
+        double[] resultGenes = parents[0];
+
+        if (rng.nextDouble() < crossoverRate) {
+            // Select crossover points
+            Deque<Integer> crossoverPoints = getCrossoverPointsGenerator(parents[0].length).getCrossoverPoints();
+
+            // Crossover
+            resultGenes = new double[parents[0].length];
+            int currentParent = 0;
+            int nextCrossover = crossoverPoints.pop();
+            for (int i = 0; i < resultGenes.length; ++i) {
+                if (i == nextCrossover) {
+                    currentParent = currentParent == 0 ? 1 : 0;
+                    nextCrossover = crossoverPoints.pop();
+                }
+                resultGenes[i] = parents[currentParent][i];
+            }
+            isModified = true;
+        }
+
+        return new CrossoverResult(isModified, resultGenes);
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/crossover/SinglePointCrossover.java

@@ -0,0 +1,123 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.crossover;
+
+import org.apache.commons.math3.random.JDKRandomGenerator;
+import org.apache.commons.math3.random.RandomGenerator;
+import org.apache.commons.math3.random.SynchronizedRandomGenerator;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.parentselection.RandomTwoParentSelection;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.parentselection.TwoParentSelection;
+import org.nd4j.base.Preconditions;
+
+/**
+ * The single point crossover will select a random point where every genes before that point comes from one parent
+ * and after which every genes comes from the other parent.
+ *
+ * @author Alexandre Boulanger
+ */
+public class SinglePointCrossover extends TwoParentsCrossoverOperator {
+    private static final double DEFAULT_CROSSOVER_RATE = 0.85;
+
+    private final RandomGenerator rng;
+    private final double crossoverRate;
+
+    public static class Builder {
+        private double crossoverRate = DEFAULT_CROSSOVER_RATE;
+        private RandomGenerator rng;
+        private TwoParentSelection parentSelection;
+
+        /**
+         * The probability that the operator generates a crossover (default 0.85).
+         *
+         * @param rate A value between 0.0 and 1.0
+         */
+        public Builder crossoverRate(double rate) {
+            Preconditions.checkState(rate >= 0.0 && rate <= 1.0, "Rate must be between 0.0 and 1.0, got %s", rate);
+
+            this.crossoverRate = rate;
+            return this;
+        }
+
+        /**
+         * Use a supplied RandomGenerator
+         *
+         * @param rng An instance of RandomGenerator
+         */
+        public Builder randomGenerator(RandomGenerator rng) {
+            this.rng = rng;
+            return this;
+        }
+
+        /**
+         * The parent selection behavior. Default is random parent selection.
+         *
+         * @param parentSelection An instance of TwoParentSelection
+         */
+        public Builder parentSelection(TwoParentSelection parentSelection) {
+            this.parentSelection = parentSelection;
+            return this;
+        }
+
+        public SinglePointCrossover build() {
+            if (rng == null) {
+                rng = new SynchronizedRandomGenerator(new JDKRandomGenerator());
+            }
+
+            if (parentSelection == null) {
+                parentSelection = new RandomTwoParentSelection();
+            }
+
+            return new SinglePointCrossover(this);
+        }
+    }
+
+    private SinglePointCrossover(SinglePointCrossover.Builder builder) {
+        super(builder.parentSelection);
+
+        this.crossoverRate = builder.crossoverRate;
+        this.rng = builder.rng;
+    }
+
+    /**
+     * Has a probability <i>crossoverRate</i> of performing the crossover where the operator will select a random crossover point.<br>
+     * Each gene before this point comes from one of the two parents and each gene at or after this point comes from the other parent.
+     * Otherwise, returns the genes of a random parent.
+     *
+     * @return The crossover result. See {@link CrossoverResult}.
+     */
+    public CrossoverResult crossover() {
+        double[][] parents = parentSelection.selectParents();
+
+        boolean isModified = false;
+        double[] resultGenes = parents[0];
+
+        if (rng.nextDouble() < crossoverRate) {
+            int chromosomeLength = parents[0].length;
+
+            // Crossover
+            resultGenes = new double[chromosomeLength];
+
+            int crossoverPoint = rng.nextInt(chromosomeLength);
+            for (int i = 0; i < resultGenes.length; ++i) {
+                resultGenes[i] = ((i < crossoverPoint) ? parents[0] : parents[1])[i];
+            }
+            isModified = true;
+        }
+
+        return new CrossoverResult(isModified, resultGenes);
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/crossover/TwoParentsCrossoverOperator.java

@@ -0,0 +1,46 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.crossover;
+
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.parentselection.TwoParentSelection;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.population.PopulationModel;
+
+/**
+ * Abstract class for all crossover operators that applies to two parents.
+ *
+ * @author Alexandre Boulanger
+ */
+public abstract class TwoParentsCrossoverOperator extends CrossoverOperator {
+
+    protected final TwoParentSelection parentSelection;
+
+    /**
+     * @param parentSelection A parent selection that selects two parents.
+     */
+    protected TwoParentsCrossoverOperator(TwoParentSelection parentSelection) {
+        this.parentSelection = parentSelection;
+    }
+
+    /**
+     * Will be called by the selection operator once the population model is instantiated.
+     */
+    @Override
+    public void initializeInstance(PopulationModel populationModel) {
+        super.initializeInstance(populationModel);
+        parentSelection.initializeInstance(populationModel.getPopulation());
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/crossover/UniformCrossover.java

@@ -0,0 +1,136 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.crossover;
+
+import org.apache.commons.math3.random.JDKRandomGenerator;
+import org.apache.commons.math3.random.RandomGenerator;
+import org.apache.commons.math3.random.SynchronizedRandomGenerator;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.parentselection.RandomTwoParentSelection;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.parentselection.TwoParentSelection;
+import org.nd4j.base.Preconditions;
+
+/**
+ * The uniform crossover will, for each gene, randomly select the parent that donates the gene.
+ *
+ * @author Alexandre Boulanger
+ */
+public class UniformCrossover extends TwoParentsCrossoverOperator {
+    private static final double DEFAULT_CROSSOVER_RATE = 0.85;
+    private static final double DEFAULT_PARENT_BIAS_FACTOR = 0.5;
+
+    private final double crossoverRate;
+    private final double parentBiasFactor;
+    private final RandomGenerator rng;
+
+    public static class Builder {
+        private double crossoverRate = DEFAULT_CROSSOVER_RATE;
+        private double parentBiasFactor = DEFAULT_PARENT_BIAS_FACTOR;
+        private RandomGenerator rng;
+        private TwoParentSelection parentSelection;
+
+        /**
+         * The probability that the operator generates a crossover (default 0.85).
+         *
+         * @param rate A value between 0.0 and 1.0
+         */
+        public Builder crossoverRate(double rate) {
+            Preconditions.checkState(rate >= 0.0 && rate <= 1.0, "Rate must be between 0.0 and 1.0, got %s", rate);
+
+            this.crossoverRate = rate;
+            return this;
+        }
+
+        /**
+         * A factor that will introduce a bias in the parent selection.<br>
+         *
+         * @param factor In the range [0, 1]. 0 will only select the first parent while 1 only select the second one. The default is 0.5; no bias.
+         */
+        public Builder parentBiasFactor(double factor) {
+            Preconditions.checkState(factor >= 0.0 && factor <= 1.0, "Factor must be between 0.0 and 1.0, got %s",
+                            factor);
+
+            this.parentBiasFactor = factor;
+            return this;
+        }
+
+        /**
+         * Use a supplied RandomGenerator
+         *
+         * @param rng An instance of RandomGenerator
+         */
+        public Builder randomGenerator(RandomGenerator rng) {
+            this.rng = rng;
+            return this;
+        }
+
+        /**
+         * The parent selection behavior. Default is random parent selection.
+         *
+         * @param parentSelection An instance of TwoParentSelection
+         */
+        public Builder parentSelection(TwoParentSelection parentSelection) {
+            this.parentSelection = parentSelection;
+            return this;
+        }
+
+        public UniformCrossover build() {
+            if (rng == null) {
+                rng = new SynchronizedRandomGenerator(new JDKRandomGenerator());
+            }
+            if (parentSelection == null) {
+                parentSelection = new RandomTwoParentSelection();
+            }
+            return new UniformCrossover(this);
+        }
+    }
+
+    private UniformCrossover(UniformCrossover.Builder builder) {
+        super(builder.parentSelection);
+
+        this.crossoverRate = builder.crossoverRate;
+        this.parentBiasFactor = builder.parentBiasFactor;
+        this.rng = builder.rng;
+    }
+
+    /**
+     * Has a probability <i>crossoverRate</i> of performing the crossover where the operator will select randomly which parent donates the gene.<br>
+     * One of the parent may be favored if the bias is different than 0.5
+     * Otherwise, returns the genes of a random parent.
+     *
+     * @return The crossover result. See {@link CrossoverResult}.
+     */
+    @Override
+    public CrossoverResult crossover() {
+        // select the parents
+        double[][] parents = parentSelection.selectParents();
+
+        double[] resultGenes = parents[0];
+        boolean isModified = false;
+
+        if (rng.nextDouble() < crossoverRate) {
+            // Crossover
+            resultGenes = new double[parents[0].length];
+
+            for (int i = 0; i < resultGenes.length; ++i) {
+                resultGenes[i] = ((rng.nextDouble() < parentBiasFactor) ? parents[0] : parents[1])[i];
+            }
+            isModified = true;
+        }
+
+        return new CrossoverResult(isModified, resultGenes);
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/crossover/parentselection/ParentSelection.java

@@ -0,0 +1,44 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.parentselection;
+
+import org.deeplearning4j.arbiter.optimize.generator.genetic.Chromosome;
+
+import java.util.List;
+
+/**
+ * Abstract class for all parent selection behaviors
+ *
+ * @author Alexandre Boulanger
+ */
+public abstract class ParentSelection {
+    protected List<Chromosome> population;
+
+    /**
+     * Will be called by the crossover operator once the population model is instantiated.
+     */
+    public void initializeInstance(List<Chromosome> population) {
+        this.population = population;
+    }
+
+    /**
+     * Performs the parent selection
+     *
+     * @return An array of parents genes. The outer array are the parents, and the inner array are the genes.
+     */
+    public abstract double[][] selectParents();
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/crossover/parentselection/RandomTwoParentSelection.java

@@ -0,0 +1,65 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.parentselection;
+
+import org.apache.commons.math3.random.JDKRandomGenerator;
+import org.apache.commons.math3.random.RandomGenerator;
+import org.apache.commons.math3.random.SynchronizedRandomGenerator;
+
+/**
+ * A parent selection behavior that returns two random parents.
+ *
+ * @author Alexandre Boulanger
+ */
+public class RandomTwoParentSelection extends TwoParentSelection {
+
+    private final RandomGenerator rng;
+
+    public RandomTwoParentSelection() {
+        this(new SynchronizedRandomGenerator(new JDKRandomGenerator()));
+    }
+
+    /**
+     * Use a supplied RandomGenerator
+     *
+     * @param rng An instance of RandomGenerator
+     */
+    public RandomTwoParentSelection(RandomGenerator rng) {
+        this.rng = rng;
+    }
+
+    /**
+     * Selects two random parents
+     *
+     * @return An array of parents genes. The outer array are the parents, and the inner array are the genes.
+     */
+    @Override
+    public double[][] selectParents() {
+        double[][] parents = new double[2][];
+
+        int parent1Idx = rng.nextInt(population.size());
+        int parent2Idx;
+        do {
+            parent2Idx = rng.nextInt(population.size());
+        } while (parent1Idx == parent2Idx);
+
+        parents[0] = population.get(parent1Idx).getGenes();
+        parents[1] = population.get(parent2Idx).getGenes();
+
+        return parents;
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/crossover/parentselection/TwoParentSelection.java

@@ -0,0 +1,25 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.parentselection;
+
+/**
+ * Abstract class for all parent selection behaviors that selects two parents.
+ *
+ * @author Alexandre Boulanger
+ */
+public abstract class TwoParentSelection extends ParentSelection {
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/crossover/utils/CrossoverPointsGenerator.java

@@ -0,0 +1,68 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.utils;
+
+import org.apache.commons.math3.random.RandomGenerator;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.KPointCrossover;
+
+import java.util.*;
+
+/**
+ * A helper class used by {@link KPointCrossover} to generate the crossover points
+ * 
+ * @author Alexandre Boulanger
+ */
+public class CrossoverPointsGenerator {
+    private final int minCrossovers;
+    private final int maxCrossovers;
+    private final RandomGenerator rng;
+    private List<Integer> parameterIndexes;
+
+    /**
+    * Constructor
+    *
+    * @param chromosomeLength The number of genes
+    * @param minCrossovers    The minimum number of crossover points to generate
+    * @param maxCrossovers    The maximum number of crossover points to generate
+    * @param rng              A RandomGenerator instance
+    */
+    public CrossoverPointsGenerator(int chromosomeLength, int minCrossovers, int maxCrossovers, RandomGenerator rng) {
+        this.minCrossovers = minCrossovers;
+        this.maxCrossovers = maxCrossovers;
+        this.rng = rng;
+        parameterIndexes = new ArrayList<Integer>();
+        for (int i = 0; i < chromosomeLength; ++i) {
+            parameterIndexes.add(i);
+        }
+    }
+
+    /**
+    * Generate a list of crossover points.
+    *
+    * @return An ordered list of crossover point indexes and with Integer.MAX_VALUE as the last element
+    */
+    public Deque<Integer> getCrossoverPoints() {
+        Collections.shuffle(parameterIndexes);
+        List<Integer> crossoverPointLists =
+                        parameterIndexes.subList(0, rng.nextInt(maxCrossovers - minCrossovers) + minCrossovers);
+        Collections.sort(crossoverPointLists);
+        Deque<Integer> crossoverPoints = new ArrayDeque<Integer>(crossoverPointLists);
+        crossoverPoints.add(Integer.MAX_VALUE);
+
+        return crossoverPoints;
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/culling/CullOperator.java

@@ -0,0 +1,41 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.culling;
+
+import org.deeplearning4j.arbiter.optimize.generator.genetic.population.PopulationModel;
+
+/**
+ * The cull operator will remove from the population the least desirables chromosomes.
+ *
+ * @author Alexandre Boulanger
+ */
+public interface CullOperator {
+    /**
+     * Will be called by the population model once created.
+     */
+    void initializeInstance(PopulationModel populationModel);
+
+    /**
+     * Cull the population to the culled size.
+     */
+    void cullPopulation();
+
+    /**
+     * @return The target population size after culling.
+     */
+    int getCulledSize();
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/culling/LeastFitCullOperator.java

@@ -0,0 +1,50 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.culling;
+
+/**
+ * An elitist cull operator that discards the chromosomes with the worst fitness while keeping the best ones.
+ *
+ * @author Alexandre Boulanger
+ */
+public class LeastFitCullOperator extends RatioCullOperator {
+
+    /**
+     * The default cull ratio is 1/3.
+     */
+    public LeastFitCullOperator() {
+        super();
+    }
+
+    /**
+     * @param cullRatio The ratio of the maximum population size to be culled.<br>
+     * For example, a ratio of 1/3 on a population with a maximum size of 30 will cull back a given population to 20.
+     */
+    public LeastFitCullOperator(double cullRatio) {
+        super(cullRatio);
+    }
+
+    /**
+     * Will discard the chromosomes with the worst fitness until the population size fall back at the culled size.
+     */
+    @Override
+    public void cullPopulation() {
+        while (population.size() > culledSize) {
+            population.remove(population.size() - 1);
+        }
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/culling/RatioCullOperator.java

@@ -0,0 +1,70 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.culling;
+
+import org.deeplearning4j.arbiter.optimize.generator.genetic.Chromosome;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.population.PopulationModel;
+import org.nd4j.base.Preconditions;
+
+import java.util.List;
+
+/**
+ * An abstract base for cull operators that culls back the population to a ratio of its maximum size.
+ *
+ * @author Alexandre Boulanger
+ */
+public abstract class RatioCullOperator implements CullOperator {
+    private static final double DEFAULT_CULL_RATIO = 1.0 / 3.0;
+    protected int culledSize;
+    protected List<Chromosome> population;
+    protected final double cullRatio;
+
+    /**
+     * @param cullRatio The ratio of the maximum population size to be culled.<br>
+     * For example, a ratio of 1/3 on a population with a maximum size of 30 will cull back a given population to 20.
+     */
+    public RatioCullOperator(double cullRatio) {
+        Preconditions.checkState(cullRatio >= 0.0 && cullRatio <= 1.0, "Cull ratio must be between 0.0 and 1.0, got %s",
+                        cullRatio);
+
+        this.cullRatio = cullRatio;
+    }
+
+    /**
+     * The default cull ratio is 1/3
+     */
+    public RatioCullOperator() {
+        this(DEFAULT_CULL_RATIO);
+    }
+
+    /**
+     * Will be called by the population model once created.
+     */
+    public void initializeInstance(PopulationModel populationModel) {
+        this.population = populationModel.getPopulation();
+        culledSize = (int) (populationModel.getPopulationSize() * (1.0 - cullRatio) + 0.5);
+    }
+
+    /**
+     * @return The target population size after culling.
+     */
+    @Override
+    public int getCulledSize() {
+        return culledSize;
+    }
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/exceptions/GeneticGenerationException.java

@@ -0,0 +1,23 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.exceptions;
+
+public class GeneticGenerationException extends RuntimeException {
+    public GeneticGenerationException(String message) {
+        super(message);
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/mutation/MutationOperator.java

@@ -0,0 +1,33 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.mutation;
+
+/**
+ * The mutation operator will apply a mutation to the given genes.
+ *
+ * @author Alexandre Boulanger
+ */
+public interface MutationOperator {
+
+    /**
+     * Performs a mutation.
+     *
+     * @param genes The genes to be mutated
+     * @return True if the genes were mutated, otherwise false.
+     */
+    boolean mutate(double[] genes);
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/mutation/RandomMutationOperator.java

@@ -0,0 +1,93 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.mutation;
+
+import org.apache.commons.math3.random.JDKRandomGenerator;
+import org.apache.commons.math3.random.RandomGenerator;
+import org.apache.commons.math3.random.SynchronizedRandomGenerator;
+import org.nd4j.base.Preconditions;
+
+/**
+ * A mutation operator where each gene has a chance of being mutated with a <i>mutation rate</i> probability.
+ *
+ * @author Alexandre Boulanger
+ */
+public class RandomMutationOperator implements MutationOperator {
+    private static final double DEFAULT_MUTATION_RATE = 0.005;
+
+    private final double mutationRate;
+    private final RandomGenerator rng;
+
+    public static class Builder {
+        private double mutationRate = DEFAULT_MUTATION_RATE;
+        private RandomGenerator rng;
+
+        /**
+         * Each gene will have this probability of being mutated.
+         *
+         * @param rate The mutation rate. (default 0.005)
+         */
+        public Builder mutationRate(double rate) {
+            Preconditions.checkState(rate >= 0.0 && rate <= 1.0, "Rate must be between 0.0 and 1.0, got %s", rate);
+
+            this.mutationRate = rate;
+            return this;
+        }
+
+        /**
+         * Use a supplied RandomGenerator
+         *
+         * @param rng An instance of RandomGenerator
+         */
+        public Builder randomGenerator(RandomGenerator rng) {
+            this.rng = rng;
+            return this;
+        }
+
+        public RandomMutationOperator build() {
+            if (rng == null) {
+                rng = new SynchronizedRandomGenerator(new JDKRandomGenerator());
+            }
+            return new RandomMutationOperator(this);
+        }
+    }
+
+    private RandomMutationOperator(RandomMutationOperator.Builder builder) {
+        this.mutationRate = builder.mutationRate;
+        this.rng = builder.rng;
+    }
+
+    /**
+     * Performs the mutation. Each gene has a <i>mutation rate</i> probability of being mutated.
+     *
+     * @param genes The genes to be mutated
+     * @return True if the genes were mutated, otherwise false.
+     */
+    @Override
+    public boolean mutate(double[] genes) {
+        boolean hasMutation = false;
+
+        for (int i = 0; i < genes.length; ++i) {
+            if (rng.nextDouble() < mutationRate) {
+                genes[i] = rng.nextDouble();
+                hasMutation = true;
+            }
+        }
+
+        return hasMutation;
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/population/EmptyPopulationInitializer.java

@@ -0,0 +1,41 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.population;
+
+import org.deeplearning4j.arbiter.optimize.generator.genetic.Chromosome;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A population initializer that build an empty population.
+ *
+ * @author Alexandre Boulanger
+ */
+public class EmptyPopulationInitializer implements PopulationInitializer {
+
+    /**
+     * Initialize an empty population
+     *
+     * @param size The maximum size of the population.
+     * @return The initialized population.
+     */
+    @Override
+    public List<Chromosome> getInitializedPopulation(int size) {
+        return new ArrayList<>(size);
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/population/PopulationInitializer.java

@@ -0,0 +1,36 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.population;
+
+import org.deeplearning4j.arbiter.optimize.generator.genetic.Chromosome;
+
+import java.util.List;
+
+/**
+ * An initializer that construct the population used by the population model.
+ *
+ * @author Alexandre Boulanger
+ */
+public interface PopulationInitializer {
+    /**
+     * Called by the population model to construct the population
+     *
+     * @param size The maximum size of the population
+     * @return An initialized population
+     */
+    List<Chromosome> getInitializedPopulation(int size);
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/population/PopulationListener.java

@@ -0,0 +1,35 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.population;
+
+import org.deeplearning4j.arbiter.optimize.generator.genetic.Chromosome;
+
+import java.util.List;
+
+/**
+ * A listener that is called when the population changes.
+ *
+ * @author Alexandre Boulanger
+ */
+public interface PopulationListener {
+    /**
+     * Called after the population has changed.
+     *
+     * @param population The population after it has changed.
+     */
+    void onChanged(List<Chromosome> population);
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/population/PopulationModel.java

@@ -0,0 +1,182 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.population;
+
+import lombok.Getter;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.Chromosome;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.culling.CullOperator;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.culling.LeastFitCullOperator;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+/**
+ * The population model handles all aspects of the population (initialization, additions and culling)
+ *
+ * @author Alexandre Boulanger
+ */
+public class PopulationModel {
+    private static final int DEFAULT_POPULATION_SIZE = 30;
+
+    private final CullOperator cullOperator;
+    private final List<PopulationListener> populationListeners = new ArrayList<>();
+    private Comparator<Chromosome> chromosomeComparator;
+
+    /**
+     * The maximum population size
+     */
+    @Getter
+    private final int populationSize;
+
+    /**
+     * The population
+     */
+    @Getter
+    public final List<Chromosome> population;
+
+    /**
+     * A comparator used when higher fitness value is better
+     */
+    public static class MaximizeScoreComparator implements Comparator<Chromosome> {
+        @Override
+        public int compare(Chromosome lhs, Chromosome rhs) {
+            return -Double.compare(lhs.getFitness(), rhs.getFitness());
+        }
+    }
+
+    /**
+     * A comparator used when lower fitness value is better
+     */
+    public static class MinimizeScoreComparator implements Comparator<Chromosome> {
+        @Override
+        public int compare(Chromosome lhs, Chromosome rhs) {
+            return Double.compare(lhs.getFitness(), rhs.getFitness());
+        }
+    }
+
+    public static class Builder {
+        private int populationSize = DEFAULT_POPULATION_SIZE;
+        private PopulationInitializer populationInitializer;
+        private CullOperator cullOperator;
+
+        /**
+         * Use an alternate population initialization behavior. Default is empty population.
+         *
+         * @param populationInitializer An instance of PopulationInitializer
+         */
+        public Builder populationInitializer(PopulationInitializer populationInitializer) {
+            this.populationInitializer = populationInitializer;
+            return this;
+        }
+
+        /**
+         * The maximum population size. <br>
+         * If using a ratio based culling, using a population with culled size of around 1.5 to 2 times the number of genes generally gives good results.
+         * (e.g. For a chromosome having 10 genes, the culled size should be between 15 and 20. And with a cull ratio of 1/3 we should set the population size to 23 to 30. (15 / (1 - 1/3)), rounded up)
+         *
+         * @param size The maximum size of the population
+         */
+        public Builder populationSize(int size) {
+            populationSize = size;
+            return this;
+        }
+
+        /**
+         * Use an alternate cull operator behavior. Default is least fit culling.
+         *
+         * @param cullOperator An instance of a CullOperator
+         */
+        public Builder cullOperator(CullOperator cullOperator) {
+            this.cullOperator = cullOperator;
+            return this;
+        }
+
+        public PopulationModel build() {
+            if (cullOperator == null) {
+                cullOperator = new LeastFitCullOperator();
+            }
+
+            if (populationInitializer == null) {
+                populationInitializer = new EmptyPopulationInitializer();
+            }
+
+            return new PopulationModel(this);
+        }
+
+    }
+
+    public PopulationModel(PopulationModel.Builder builder) {
+        populationSize = builder.populationSize;
+        population = new ArrayList<>(builder.populationSize);
+        PopulationInitializer populationInitializer = builder.populationInitializer;
+
+        List<Chromosome> initializedPopulation = populationInitializer.getInitializedPopulation(populationSize);
+        population.clear();
+        population.addAll(initializedPopulation);
+
+        cullOperator = builder.cullOperator;
+        cullOperator.initializeInstance(this);
+    }
+
+    /**
+     * Called by the GeneticSearchCandidateGenerator
+     */
+    public void initializeInstance(boolean minimizeScore) {
+        chromosomeComparator = minimizeScore ? new MinimizeScoreComparator() : new MaximizeScoreComparator();
+    }
+
+    /**
+     * Add a PopulationListener to the list of change listeners
+     * @param listener A PopulationListener instance
+     */
+    public void addListener(PopulationListener listener) {
+        populationListeners.add(listener);
+    }
+
+    /**
+     * Add a Chromosome to the population and call the PopulationListeners. Culling may be triggered.
+     *
+     * @param element The chromosome to be added
+     */
+    public void add(Chromosome element) {
+        if (population.size() == populationSize) {
+            cullOperator.cullPopulation();
+        }
+
+        population.add(element);
+
+        Collections.sort(population, chromosomeComparator);
+
+        triggerPopulationChangedListeners(population);
+    }
+
+    /**
+     * @return Return false when the population is below the culled size, otherwise true. <br>
+     * Used by the selection operator to know if the population is still too small and should generate random genes.
+     */
+    public boolean isReadyToBreed() {
+        return population.size() >= cullOperator.getCulledSize();
+    }
+
+    private void triggerPopulationChangedListeners(List<Chromosome> population) {
+        for (PopulationListener listener : populationListeners) {
+            listener.onChanged(population);
+        }
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/selection/GeneticSelectionOperator.java

@@ -0,0 +1,197 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.selection;
+
+import org.apache.commons.math3.random.JDKRandomGenerator;
+import org.apache.commons.math3.random.RandomGenerator;
+import org.apache.commons.math3.random.SynchronizedRandomGenerator;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.ChromosomeFactory;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.CrossoverOperator;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.CrossoverResult;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.crossover.SinglePointCrossover;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.exceptions.GeneticGenerationException;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.mutation.MutationOperator;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.mutation.RandomMutationOperator;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.population.PopulationModel;
+
+import java.util.Arrays;
+
+/**
+ * A selection operator that will generate random genes initially. Once the population has reached the culled size,
+ * will start to generate offsprings of parents selected in the population.
+ *
+ * @author Alexandre Boulanger
+ */
+public class GeneticSelectionOperator extends SelectionOperator {
+
+    private final static int PREVIOUS_GENES_TO_KEEP = 100;
+    private final static int MAX_NUM_GENERATION_ATTEMPTS = 1024;
+
+    private final CrossoverOperator crossoverOperator;
+    private final MutationOperator mutationOperator;
+    private final RandomGenerator rng;
+    private double[][] previousGenes = new double[PREVIOUS_GENES_TO_KEEP][];
+    private int previousGenesIdx = 0;
+
+    public static class Builder {
+        private ChromosomeFactory chromosomeFactory;
+        private PopulationModel populationModel;
+        private CrossoverOperator crossoverOperator;
+        private MutationOperator mutationOperator;
+        private RandomGenerator rng;
+
+        /**
+         * Use an alternate crossover behavior. Default is SinglePointCrossover.
+         *
+         * @param crossoverOperator An instance of CrossoverOperator
+         */
+        public Builder crossoverOperator(CrossoverOperator crossoverOperator) {
+            this.crossoverOperator = crossoverOperator;
+            return this;
+        }
+
+        /**
+         * Use an alternate mutation behavior. Default is RandomMutationOperator.
+         *
+         * @param mutationOperator An instance of MutationOperator
+         */
+        public Builder mutationOperator(MutationOperator mutationOperator) {
+            this.mutationOperator = mutationOperator;
+            return this;
+        }
+
+        /**
+         * Use a supplied RandomGenerator
+         *
+         * @param rng An instance of RandomGenerator
+         */
+        public Builder randomGenerator(RandomGenerator rng) {
+            this.rng = rng;
+            return this;
+        }
+
+        public GeneticSelectionOperator build() {
+            if (crossoverOperator == null) {
+                crossoverOperator = new SinglePointCrossover.Builder().build();
+            }
+
+            if (mutationOperator == null) {
+                mutationOperator = new RandomMutationOperator.Builder().build();
+            }
+
+            if (rng == null) {
+                rng = new SynchronizedRandomGenerator(new JDKRandomGenerator());
+            }
+
+            return new GeneticSelectionOperator(crossoverOperator, mutationOperator, rng);
+        }
+    }
+
+    private GeneticSelectionOperator(CrossoverOperator crossoverOperator, MutationOperator mutationOperator,
+                    RandomGenerator rng) {
+        this.crossoverOperator = crossoverOperator;
+        this.mutationOperator = mutationOperator;
+        this.rng = rng;
+    }
+
+    /**
+     * Called by GeneticSearchCandidateGenerator
+     */
+    @Override
+    public void initializeInstance(PopulationModel populationModel, ChromosomeFactory chromosomeFactory) {
+        super.initializeInstance(populationModel, chromosomeFactory);
+        crossoverOperator.initializeInstance(populationModel);
+    }
+
+    /**
+     * Build a new set of genes. Has two distinct modes of operation
+     * <ul>
+     * <li>Before the population has reached the culled size: will return a random set of genes.</li>
+     * <li>After: Parents will be selected among the population, a crossover will be applied followed by a mutation.</li>
+     * </ul>
+     * @return Returns the generated set of genes
+     * @throws GeneticGenerationException If buildNextGenes() can't generate a set that has not already been tried,
+     *                                               or if the crossover and the mutation operators can't generate a set,
+     *                                               this exception is thrown.
+     */
+    @Override
+    public double[] buildNextGenes() {
+        double[] result;
+
+        boolean hasAlreadyBeenTried;
+        int attemptsRemaining = MAX_NUM_GENERATION_ATTEMPTS;
+        do {
+            if (populationModel.isReadyToBreed()) {
+                result = buildOffspring();
+            } else {
+                result = buildRandomGenes();
+            }
+
+            hasAlreadyBeenTried = hasAlreadyBeenTried(result);
+            if (hasAlreadyBeenTried && --attemptsRemaining == 0) {
+                throw new GeneticGenerationException("Failed to generate a set of genes not already tried.");
+            }
+        } while (hasAlreadyBeenTried);
+
+        previousGenes[previousGenesIdx] = result;
+        previousGenesIdx = ++previousGenesIdx % previousGenes.length;
+
+        return result;
+    }
+
+    private boolean hasAlreadyBeenTried(double[] genes) {
+        for (int i = 0; i < previousGenes.length; ++i) {
+            double[] current = previousGenes[i];
+            if (current != null && Arrays.equals(current, genes)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    private double[] buildOffspring() {
+        double[] offspringValues;
+
+        boolean isModified;
+        int attemptsRemaining = MAX_NUM_GENERATION_ATTEMPTS;
+        do {
+            CrossoverResult crossoverResult = crossoverOperator.crossover();
+            offspringValues = crossoverResult.getGenes();
+            isModified = crossoverResult.isModified();
+            isModified |= mutationOperator.mutate(offspringValues);
+
+            if (!isModified && --attemptsRemaining == 0) {
+                throw new GeneticGenerationException(
+                                String.format("Crossover and mutation operators failed to generate a new set of genes after %s attempts.",
+                                                MAX_NUM_GENERATION_ATTEMPTS));
+            }
+        } while (!isModified);
+
+        return offspringValues;
+    }
+
+    private double[] buildRandomGenes() {
+        double[] randomValues = new double[chromosomeFactory.getChromosomeLength()];
+        for (int i = 0; i < randomValues.length; ++i) {
+            randomValues[i] = rng.nextDouble();
+        }
+
+        return randomValues;
+    }
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/genetic/selection/SelectionOperator.java

@@ -0,0 +1,44 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.genetic.selection;
+
+import org.deeplearning4j.arbiter.optimize.generator.genetic.ChromosomeFactory;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.population.PopulationModel;
+
+/**
+ * An abstract class for all selection operators. Used by the GeneticSearchCandidateGenerator to generate new candidates.
+ *
+ * @author Alexandre Boulanger
+ */
+public abstract class SelectionOperator {
+    protected PopulationModel populationModel;
+    protected ChromosomeFactory chromosomeFactory;
+
+    /**
+     * Called by GeneticSearchCandidateGenerator
+     */
+    public void initializeInstance(PopulationModel populationModel, ChromosomeFactory chromosomeFactory) {
+
+        this.populationModel = populationModel;
+        this.chromosomeFactory = chromosomeFactory;
+    }
+
+    /**
+     * Generate a new set of genes.
+     */
+    public abstract double[] buildNextGenes();
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/generator/util/SerializedSupplier.java

@@ -0,0 +1,46 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.generator.util;
+
+import org.nd4j.linalg.function.Supplier;
+
+import java.io.*;
+
+public class SerializedSupplier<T> implements Serializable, Supplier<T> {
+
+    private byte[] asBytes;
+
+    public SerializedSupplier(T obj){
+        try(ByteArrayOutputStream baos = new ByteArrayOutputStream(); ObjectOutputStream oos = new ObjectOutputStream(baos)){
+            oos.writeObject(obj);
+            oos.flush();
+            oos.close();
+            asBytes = baos.toByteArray();
+        } catch (Exception e){
+            throw new RuntimeException("Error serializing object - must be serializable",e);
+        }
+    }
+
+    @Override
+    public T get() {
+        try(ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(asBytes))){
+            return (T)ois.readObject();
+        } catch (Exception e){
+            throw new RuntimeException("Error deserializing object",e);
+        }
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/parameter/BooleanSpace.java

@@ -0,0 +1,76 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.parameter;
+
+import lombok.EqualsAndHashCode;
+import org.deeplearning4j.arbiter.optimize.api.ParameterSpace;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * BooleanParameterSpace is a {@code ParameterSpace<Boolean>}; Defines {True, False} as a parameter space
+ * If argument to setValue is less than or equal to 0.5 it will return True else False
+ *
+ * @author susaneraly
+ */
+@EqualsAndHashCode
+public class BooleanSpace implements ParameterSpace<Boolean> {
+    private int index = -1;
+
+    @Override
+    public Boolean getValue(double[] input) {
+        if (index == -1) {
+            throw new IllegalStateException("Cannot get value: ParameterSpace index has not been set");
+        }
+        if (input[index] <= 0.5) return Boolean.TRUE;
+        else return Boolean.FALSE;
+    }
+
+    @Override
+    public int numParameters() {
+        return 1;
+    }
+
+    @Override
+    public List<ParameterSpace> collectLeaves() {
+        return Collections.singletonList((ParameterSpace) this);
+    }
+
+    @Override
+    public Map<String, ParameterSpace> getNestedSpaces() {
+        return Collections.emptyMap();
+    }
+
+    @Override
+    public boolean isLeaf() {
+        return true;
+    }
+
+    @Override
+    public void setIndices(int... indices) {
+        if (indices == null || indices.length != 1)
+            throw new IllegalArgumentException("Invalid index");
+        this.index = indices[0];
+    }
+
+    @Override
+    public String toString() {
+        return "BooleanSpace()";
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/parameter/FixedValue.java

@@ -0,0 +1,87 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.parameter;
+
+import lombok.EqualsAndHashCode;
+import org.deeplearning4j.arbiter.optimize.api.ParameterSpace;
+import org.deeplearning4j.arbiter.optimize.serde.jackson.GenericDeserializer;
+import org.deeplearning4j.arbiter.optimize.serde.jackson.GenericSerializer;
+import org.deeplearning4j.arbiter.util.ObjectUtils;
+import org.nd4j.shade.jackson.annotation.JsonCreator;
+import org.nd4j.shade.jackson.annotation.JsonIgnoreProperties;
+import org.nd4j.shade.jackson.annotation.JsonProperty;
+import org.nd4j.shade.jackson.databind.annotation.JsonDeserialize;
+import org.nd4j.shade.jackson.databind.annotation.JsonSerialize;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * FixedValue is a ParameterSpace that defines only a single fixed value
+ *
+ * @param <T> Type of (fixed) value
+ */
+@EqualsAndHashCode
+public class FixedValue<T> implements ParameterSpace<T> {
+    @JsonSerialize(using = GenericSerializer.class)
+    @JsonDeserialize(using = GenericDeserializer.class)
+    private Object value;
+    private int index;
+
+    @JsonCreator
+    public FixedValue(@JsonProperty("value") T value) {
+        this.value = value;
+    }
+
+    @Override
+    public String toString() {
+        return "FixedValue(" + ObjectUtils.valueToString(value) + ")";
+    }
+
+    @Override
+    public T getValue(double[] input) {
+        return (T) value;
+    }
+
+    @Override
+    public int numParameters() {
+        return 0;
+    }
+
+    @Override
+    public List<ParameterSpace> collectLeaves() {
+        return Collections.emptyList();
+    }
+
+    @Override
+    public Map<String, ParameterSpace> getNestedSpaces() {
+        return Collections.emptyMap();
+    }
+
+    @Override
+    public boolean isLeaf() {
+        return true;
+    }
+
+    @Override
+    public void setIndices(int... indices) {
+        if (indices != null && indices.length != 0)
+            throw new IllegalArgumentException(
+                            "Invalid call: FixedValue ParameterSpace " + "should not be given an index (0 params)");
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/parameter/continuous/ContinuousParameterSpace.java

@@ -0,0 +1,137 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.parameter.continuous;
+
+import org.apache.commons.math3.distribution.RealDistribution;
+import org.apache.commons.math3.distribution.UniformRealDistribution;
+import org.deeplearning4j.arbiter.optimize.api.ParameterSpace;
+import org.deeplearning4j.arbiter.optimize.distribution.DistributionUtils;
+import org.deeplearning4j.arbiter.optimize.serde.jackson.RealDistributionDeserializer;
+import org.deeplearning4j.arbiter.optimize.serde.jackson.RealDistributionSerializer;
+import org.nd4j.shade.jackson.annotation.JsonIgnoreProperties;
+import org.nd4j.shade.jackson.annotation.JsonProperty;
+import org.nd4j.shade.jackson.databind.annotation.JsonDeserialize;
+import org.nd4j.shade.jackson.databind.annotation.JsonSerialize;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * ContinuousParametSpace is a {@code ParameterSpace<Double>} that (optionally) takes an Apache Commons
+ * {@link RealDistribution} when used for random sampling (such as in a RandomSearchCandidateGenerator)
+ *
+ * @author Alex Black
+ */
+public class ContinuousParameterSpace implements ParameterSpace<Double> {
+
+    //Need to use custom serializers/deserializers for commons RealDistribution instances
+    @JsonSerialize(using = RealDistributionSerializer.class)
+    @JsonDeserialize(using = RealDistributionDeserializer.class)
+    private RealDistribution distribution;
+    private int index = -1;
+
+    /**
+     * ContinuousParameterSpace with uniform distribution between the minimum and maximum values
+     *
+     * @param min Minimum value that can be generated
+     * @param max Maximum value that can be generated
+     */
+    public ContinuousParameterSpace(double min, double max) {
+        this(new UniformRealDistribution(min, max));
+    }
+
+    /**
+     * ConditiousParameterSpcae wiht a specified probability distribution. The provided distribution defines the min/max
+     * values, and (for random search, etc) will be used when generating random values
+     *
+     * @param distribution Distribution to sample from
+     */
+    public ContinuousParameterSpace(@JsonProperty("distribution") RealDistribution distribution) {
+        this.distribution = distribution;
+    }
+
+
+    @Override
+    public Double getValue(double[] input) {
+        if (index == -1) {
+            throw new IllegalStateException("Cannot get value: ParameterSpace index has not been set");
+        }
+        return distribution.inverseCumulativeProbability(input[index]);
+    }
+
+    @Override
+    public int numParameters() {
+        return 1;
+    }
+
+    @Override
+    public List<ParameterSpace> collectLeaves() {
+        return Collections.singletonList((ParameterSpace) this);
+    }
+
+    @Override
+    public Map<String, ParameterSpace> getNestedSpaces() {
+        return Collections.emptyMap();
+    }
+
+    @Override
+    public boolean isLeaf() {
+        return true;
+    }
+
+    @Override
+    public void setIndices(int... indices) {
+        if (indices == null || indices.length != 1) {
+            throw new IllegalArgumentException("Invalid index");
+        }
+        this.index = indices[0];
+    }
+
+
+    @Override
+    public String toString() {
+        if (distribution instanceof UniformRealDistribution) {
+            return "ContinuousParameterSpace(min=" + distribution.getSupportLowerBound() + ",max="
+                            + distribution.getSupportUpperBound() + ")";
+        } else {
+            return "ContinuousParameterSpace(" + distribution + ")";
+        }
+    }
+
+    public boolean equals(Object o) {
+        if (o == this)
+            return true;
+        if (!(o instanceof ContinuousParameterSpace))
+            return false;
+        final ContinuousParameterSpace other = (ContinuousParameterSpace) o;
+        if (distribution == null ? other.distribution != null
+                        : !DistributionUtils.distributionsEqual(distribution, other.distribution))
+            return false;
+        if (this.index != other.index)
+            return false;
+        return true;
+    }
+
+    public int hashCode() {
+        final int PRIME = 59;
+        int result = 1;
+        result = result * PRIME + (distribution == null ? 43 : distribution.getClass().hashCode());
+        result = result * PRIME + this.index;
+        return result;
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/parameter/discrete/DiscreteParameterSpace.java

@@ -0,0 +1,113 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.parameter.discrete;
+
+import lombok.EqualsAndHashCode;
+import org.deeplearning4j.arbiter.optimize.api.ParameterSpace;
+import org.deeplearning4j.arbiter.util.ObjectUtils;
+import org.nd4j.shade.jackson.annotation.JsonIgnoreProperties;
+import org.nd4j.shade.jackson.annotation.JsonProperty;
+import org.nd4j.shade.jackson.databind.annotation.JsonSerialize;
+
+import java.util.*;
+
+/**
+ * A DiscreteParameterSpace is used for a set of un-ordered values
+ *
+ * @param <P> Parameter type
+ * @author Alex Black
+ */
+@EqualsAndHashCode
+public class DiscreteParameterSpace<P> implements ParameterSpace<P> {
+
+    @JsonSerialize
+    private List<P> values;
+    private int index = -1;
+
+    public DiscreteParameterSpace(@JsonProperty("values") P... values) {
+        if (values != null)
+            this.values = Arrays.asList(values);
+    }
+
+    public DiscreteParameterSpace(Collection<P> values) {
+        this.values = new ArrayList<>(values);
+    }
+
+    public int numValues() {
+        return values.size();
+    }
+
+    @Override
+    public P getValue(double[] input) {
+        if (index == -1) {
+            throw new IllegalStateException("Cannot get value: ParameterSpace index has not been set");
+        }
+        if (values == null)
+            throw new IllegalStateException("Values are null.");
+        //Map a value in range [0,1] to one of the list of values
+        //First value: [0,width], second: (width,2*width], third: (3*width,4*width] etc
+        int size = values.size();
+        if (size == 1)
+            return values.get(0);
+        double width = 1.0 / size;
+        int val = (int) (input[index] / width);
+        return values.get(Math.min(val, size - 1));
+    }
+
+    @Override
+    public int numParameters() {
+        return 1;
+    }
+
+    @Override
+    public List<ParameterSpace> collectLeaves() {
+        return Collections.singletonList((ParameterSpace) this);
+    }
+
+    @Override
+    public Map<String, ParameterSpace> getNestedSpaces() {
+        return Collections.emptyMap();
+    }
+
+    @Override
+    public boolean isLeaf() {
+        return true;
+    }
+
+    @Override
+    public void setIndices(int... indices) {
+        if (indices == null || indices.length != 1) {
+            throw new IllegalArgumentException("Invalid index");
+        }
+        this.index = indices[0];
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder sb = new StringBuilder();
+        sb.append("DiscreteParameterSpace(");
+        int n = values.size();
+        for (int i = 0; i < n; i++) {
+            P value = values.get(i);
+            sb.append(ObjectUtils.valueToString(value));
+            sb.append((i == n - 1 ? ")" : ","));
+        }
+        return sb.toString();
+    }
+
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/parameter/integer/IntegerParameterSpace.java

@@ -0,0 +1,151 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.parameter.integer;
+
+import lombok.NoArgsConstructor;
+import org.apache.commons.math3.distribution.IntegerDistribution;
+import org.apache.commons.math3.distribution.UniformIntegerDistribution;
+import org.deeplearning4j.arbiter.optimize.api.ParameterSpace;
+import org.deeplearning4j.arbiter.optimize.distribution.DistributionUtils;
+import org.deeplearning4j.arbiter.optimize.serde.jackson.IntegerDistributionDeserializer;
+import org.deeplearning4j.arbiter.optimize.serde.jackson.IntegerDistributionSerializer;
+import org.nd4j.shade.jackson.annotation.JsonCreator;
+import org.nd4j.shade.jackson.annotation.JsonIgnoreProperties;
+import org.nd4j.shade.jackson.annotation.JsonProperty;
+import org.nd4j.shade.jackson.databind.annotation.JsonDeserialize;
+import org.nd4j.shade.jackson.databind.annotation.JsonSerialize;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * IntegerParameterSpace is a {@code ParameterSpace<Integer>}; i.e., defines an ordered space of integers between
+ * some minimum and maximum value
+ *
+ * @author Alex Black
+ */
+@JsonIgnoreProperties({"min", "max"})
+@NoArgsConstructor
+public class IntegerParameterSpace implements ParameterSpace<Integer> {
+
+    @JsonSerialize(using = IntegerDistributionSerializer.class)
+    @JsonDeserialize(using = IntegerDistributionDeserializer.class)
+    private IntegerDistribution distribution;
+    private int index = -1;
+
+    /**
+     * Create an IntegerParameterSpace with a uniform distribution between the specified min/max (inclusive)
+     *
+     * @param min Min value, inclusive
+     * @param max Max value, inclusive
+     */
+    public IntegerParameterSpace(int min, int max) {
+        this(new UniformIntegerDistribution(min, max));
+    }
+
+    /**
+     * Crate an IntegerParametSpace from the given IntegerDistribution
+     *
+     * @param distribution Distribution to use
+     */
+    @JsonCreator
+    public IntegerParameterSpace(@JsonProperty("distribution") IntegerDistribution distribution) {
+        this.distribution = distribution;
+    }
+
+    public int getMin() {
+        return distribution.getSupportLowerBound();
+    }
+
+    public int getMax() {
+        return distribution.getSupportUpperBound();
+    }
+
+    @Override
+    public Integer getValue(double[] input) {
+        if (index == -1) {
+            throw new IllegalStateException("Cannot get value: ParameterSpace index has not been set");
+        }
+        return distribution.inverseCumulativeProbability(input[index]);
+    }
+
+    @Override
+    public int numParameters() {
+        return 1;
+    }
+
+    @Override
+    public List<ParameterSpace> collectLeaves() {
+        return Collections.singletonList((ParameterSpace) this);
+    }
+
+    @Override
+    public Map<String, ParameterSpace> getNestedSpaces() {
+        return Collections.emptyMap();
+    }
+
+    @Override
+    public boolean isLeaf() {
+        return true;
+    }
+
+    @Override
+    public void setIndices(int... indices) {
+        if (indices == null || indices.length != 1)
+            throw new IllegalArgumentException("Invalid index");
+        this.index = indices[0];
+    }
+
+    @Override
+    public String toString() {
+        if (distribution instanceof UniformIntegerDistribution) {
+            return "IntegerParameterSpace(min=" + distribution.getSupportLowerBound() + ",max="
+                            + distribution.getSupportUpperBound() + ")";
+        } else {
+            return "IntegerParameterSpace(" + distribution + ")";
+        }
+    }
+
+    public boolean equals(Object o) {
+        if (o == this)
+            return true;
+        if (!(o instanceof IntegerParameterSpace))
+            return false;
+        final IntegerParameterSpace other = (IntegerParameterSpace) o;
+        if (!other.canEqual(this))
+            return false;
+        if (distribution == null ? other.distribution != null
+                        : !DistributionUtils.distributionEquals(distribution, other.distribution))
+            return false;
+        if (this.index != other.index)
+            return false;
+        return true;
+    }
+
+    public int hashCode() {
+        final int PRIME = 59;
+        int result = 1;
+        result = result * PRIME + (distribution == null ? 43 : distribution.getClass().hashCode());
+        result = result * PRIME + this.index;
+        return result;
+    }
+
+    protected boolean canEqual(Object other) {
+        return other instanceof IntegerParameterSpace;
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/parameter/math/MathOp.java

@@ -0,0 +1,69 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.parameter.math;
+
+import org.deeplearning4j.arbiter.optimize.api.AbstractParameterSpace;
+import org.deeplearning4j.arbiter.optimize.api.ParameterSpace;
+
+import java.util.List;
+
+/**
+ * A simple parameter space that implements scalar mathematical operations on another parameter space. This allows you
+ * to do things like Y = X * 2, where X is a parameter space. For example, a layer size hyperparameter could be set
+ * using this to 2x the size of the previous layer
+ *
+ * @param <T> Type of the parameter space
+ * @author Alex Black
+ */
+public class MathOp<T extends Number> extends AbstractParameterSpace<T> {
+
+    private ParameterSpace<T> parameterSpace;
+    private Op op;
+    private T scalar;
+
+    public MathOp(ParameterSpace<T> parameterSpace, Op op, T scalar){
+        this.parameterSpace = parameterSpace;
+        this.op = op;
+        this.scalar = scalar;
+    }
+
+    @Override
+    public T getValue(double[] parameterValues) {
+        T u = parameterSpace.getValue(parameterValues);
+        return op.doOp(u, scalar);
+    }
+
+    @Override
+    public int numParameters() {
+        return parameterSpace.numParameters();
+    }
+
+    @Override
+    public List<ParameterSpace> collectLeaves() {
+        return parameterSpace.collectLeaves();
+    }
+
+    @Override
+    public boolean isLeaf() {
+        return false;
+    }
+
+    @Override
+    public void setIndices(int... indices) {
+        parameterSpace.setIndices(indices);
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/parameter/math/Op.java

@@ -0,0 +1,76 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.parameter.math;
+
+public enum Op {
+    ADD, SUB, MUL, DIV;
+
+
+    //Package private
+    <T extends Number> T doOp(T first, T second){
+        if(first instanceof Integer || first instanceof Long){
+            long result;
+            switch (this){
+                case ADD:
+                    result = Long.valueOf(first.longValue() + second.longValue());
+                    break;
+                case SUB:
+                    result = Long.valueOf(first.longValue() - second.longValue());
+                    break;
+                case MUL:
+                    result = Long.valueOf(first.longValue() * second.longValue());
+                    break;
+                case DIV:
+                    result = Long.valueOf(first.longValue() / second.longValue());
+                    break;
+                default:
+                    throw new UnsupportedOperationException("Unknown op: " + this);
+            }
+            if(first instanceof Long){
+                return (T)Long.valueOf(result);
+            } else {
+                return (T)Integer.valueOf((int)result);
+            }
+        } else if(first instanceof Double || first instanceof Float){
+            double result;
+            switch (this){
+                case ADD:
+                    result = Double.valueOf(first.doubleValue() + second.doubleValue());
+                    break;
+                case SUB:
+                    result = Double.valueOf(first.doubleValue() - second.doubleValue());
+                    break;
+                case MUL:
+                    result = Double.valueOf(first.doubleValue() * second.doubleValue());
+                    break;
+                case DIV:
+                    result = Double.valueOf(first.doubleValue() / second.doubleValue());
+                    break;
+                default:
+                    throw new UnsupportedOperationException("Unknown op: " + this);
+            }
+            if(first instanceof Double){
+                return (T)Double.valueOf(result);
+            } else {
+                return (T)Float.valueOf((float)result);
+            }
+        } else {
+            throw new UnsupportedOperationException("Not supported type: only Integer, Long, Double, Float supported" +
+                    " here. Got type: " + first.getClass());
+        }
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/parameter/math/PairMathOp.java

@@ -0,0 +1,79 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.parameter.math;
+
+import org.deeplearning4j.arbiter.optimize.api.AbstractParameterSpace;
+import org.deeplearning4j.arbiter.optimize.api.ParameterSpace;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * A simple parameter space that implements pairwise mathematical operations on another parameter space. This allows you
+ * to do things like Z = X + Y, where X and Y are parameter spaces.
+ *
+ * @param <T> Type of the parameter space
+ * @author Alex Black
+ */
+public class PairMathOp<T extends Number> extends AbstractParameterSpace<T> {
+
+    private ParameterSpace<T> first;
+    private ParameterSpace<T> second;
+    private Op op;
+
+    public PairMathOp(ParameterSpace<T> first, ParameterSpace<T> second, Op op){
+        this.first = first;
+        this.second = second;
+        this.op = op;
+    }
+
+    @Override
+    public T getValue(double[] parameterValues) {
+        T f = first.getValue(parameterValues);
+        T s = second.getValue(parameterValues);
+        return op.doOp(f, s);
+    }
+
+    @Override
+    public int numParameters() {
+        return first.numParameters() + second.numParameters();
+    }
+
+    @Override
+    public List<ParameterSpace> collectLeaves() {
+        List<ParameterSpace> l = new ArrayList<>();
+        l.addAll(first.collectLeaves());
+        l.addAll(second.collectLeaves());
+        return l;
+    }
+
+    @Override
+    public boolean isLeaf() {
+        return false;
+    }
+
+    @Override
+    public void setIndices(int... indices) {
+        int n1 = first.numParameters();
+        int n2 = second.numParameters();
+        int[] s1 = Arrays.copyOfRange(indices, 0, n1);
+        int[] s2 = Arrays.copyOfRange(indices, n1, n1+n2);
+        first.setIndices(s1);
+        second.setIndices(s2);
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/runner/BaseOptimizationRunner.java

@@ -0,0 +1,383 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.runner;
+
+import com.google.common.util.concurrent.ListenableFuture;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.commons.lang3.exception.ExceptionUtils;
+import org.deeplearning4j.arbiter.optimize.api.Candidate;
+import org.deeplearning4j.arbiter.optimize.api.OptimizationResult;
+import org.deeplearning4j.arbiter.optimize.api.data.DataProvider;
+import org.deeplearning4j.arbiter.optimize.api.data.DataSource;
+import org.deeplearning4j.arbiter.optimize.api.saving.ResultReference;
+import org.deeplearning4j.arbiter.optimize.api.score.ScoreFunction;
+import org.deeplearning4j.arbiter.optimize.api.termination.TerminationCondition;
+import org.deeplearning4j.arbiter.optimize.config.OptimizationConfiguration;
+import org.deeplearning4j.arbiter.optimize.runner.listener.StatusListener;
+
+import java.util.*;
+import java.util.concurrent.*;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+/**
+ * BaseOptimization runner: responsible for scheduling tasks, saving results using the result saver, etc.
+ *
+ * @author Alex Black
+ */
+@Slf4j
+public abstract class BaseOptimizationRunner implements IOptimizationRunner {
+    private static final int POLLING_FREQUENCY = 1;
+    private static final TimeUnit POLLING_FREQUENCY_UNIT = TimeUnit.SECONDS;
+
+    protected OptimizationConfiguration config;
+    protected Queue<Future<OptimizationResult>> queuedFutures = new ConcurrentLinkedQueue<>();
+    protected BlockingQueue<Future<OptimizationResult>> completedFutures = new LinkedBlockingQueue<>();
+    protected AtomicInteger totalCandidateCount = new AtomicInteger();
+    protected AtomicInteger numCandidatesCompleted = new AtomicInteger();
+    protected AtomicInteger numCandidatesFailed = new AtomicInteger();
+    protected Double bestScore = null;
+    protected Long bestScoreTime = null;
+    protected AtomicInteger bestScoreCandidateIndex = new AtomicInteger(-1);
+    protected List<ResultReference> allResults = new ArrayList<>();
+
+    protected Map<Integer, CandidateInfo> currentStatus = new ConcurrentHashMap<>(); //TODO: better design possible?
+
+    protected ExecutorService futureListenerExecutor;
+
+    protected List<StatusListener> statusListeners = new ArrayList<>();
+
+
+    protected BaseOptimizationRunner(OptimizationConfiguration config) {
+        this.config = config;
+
+        if (config.getTerminationConditions() == null || config.getTerminationConditions().size() == 0) {
+            throw new IllegalArgumentException("Cannot create BaseOptimizationRunner without TerminationConditions ("
+                    + "termination conditions are null or empty)");
+        }
+
+    }
+
+    protected void init() {
+        futureListenerExecutor = Executors.newFixedThreadPool(maxConcurrentTasks(), new ThreadFactory() {
+            private AtomicLong counter = new AtomicLong(0);
+
+            @Override
+            public Thread newThread(Runnable r) {
+                Thread t = Executors.defaultThreadFactory().newThread(r);
+                t.setDaemon(true);
+                t.setName("ArbiterOptimizationRunner-" + counter.getAndIncrement());
+                return t;
+            }
+        });
+    }
+
+    /**
+     *
+     */
+    @Override
+    public void execute() {
+        log.info("{}: execution started", this.getClass().getSimpleName());
+        config.setExecutionStartTime(System.currentTimeMillis());
+        for (StatusListener listener : statusListeners) {
+            listener.onInitialization(this);
+        }
+
+        //Initialize termination conditions (start timers, etc)
+        for (TerminationCondition c : config.getTerminationConditions()) {
+            c.initialize(this);
+        }
+
+        //Queue initial tasks:
+        List<Future<OptimizationResult>> tempList = new ArrayList<>(100);
+        while (true) {
+            //Otherwise: add tasks if required
+            Future<OptimizationResult> future = null;
+            try {
+                future = completedFutures.poll(POLLING_FREQUENCY, POLLING_FREQUENCY_UNIT);
+            } catch (InterruptedException e) {
+                //No op?
+            }
+            if (future != null) {
+                tempList.add(future);
+            }
+            completedFutures.drainTo(tempList);
+
+            //Process results (if any)
+            for (Future<OptimizationResult> f : tempList) {
+                queuedFutures.remove(f);
+                processReturnedTask(f);
+            }
+
+            if (tempList.size() > 0) {
+                for (StatusListener sl : statusListeners) {
+                    sl.onRunnerStatusChange(this);
+                }
+            }
+            tempList.clear();
+
+            //Check termination conditions:
+            if (terminate()) {
+                shutdown(true);
+                break;
+            }
+
+            //Add additional tasks
+            while (config.getCandidateGenerator().hasMoreCandidates() && queuedFutures.size() < maxConcurrentTasks()) {
+                Candidate candidate = config.getCandidateGenerator().getCandidate();
+                CandidateInfo status;
+                if (candidate.getException() != null) {
+                    //Failed on generation...
+                    status = processFailedCandidates(candidate);
+                } else {
+                    long created = System.currentTimeMillis();
+                    ListenableFuture<OptimizationResult> f;
+                    if(config.getDataSource() != null){
+                        f = execute(candidate, config.getDataSource(), config.getDataSourceProperties(), config.getScoreFunction());
+                    } else {
+                        f = execute(candidate, config.getDataProvider(), config.getScoreFunction());
+                    }
+                    f.addListener(new OnCompletionListener(f), futureListenerExecutor);
+                    queuedFutures.add(f);
+                    totalCandidateCount.getAndIncrement();
+
+                    status = new CandidateInfo(candidate.getIndex(), CandidateStatus.Created, null,
+                            created, null, null, candidate.getFlatParameters(), null);
+                    currentStatus.put(candidate.getIndex(), status);
+                }
+
+                for (StatusListener listener : statusListeners) {
+                    listener.onCandidateStatusChange(status, this, null);
+                }
+            }
+        }
+
+        //Process any final (completed) tasks:
+        completedFutures.drainTo(tempList);
+        for (Future<OptimizationResult> f : tempList) {
+            queuedFutures.remove(f);
+            processReturnedTask(f);
+        }
+        tempList.clear();
+
+        log.info("Optimization runner: execution complete");
+        for (StatusListener listener : statusListeners) {
+            listener.onShutdown(this);
+        }
+    }
+
+
+    private CandidateInfo processFailedCandidates(Candidate<?> candidate) {
+        //In case the candidate fails during the creation of the candidate
+
+        long time = System.currentTimeMillis();
+        String stackTrace = ExceptionUtils.getStackTrace(candidate.getException());
+        CandidateInfo newStatus = new CandidateInfo(candidate.getIndex(), CandidateStatus.Failed, null, time, time,
+                time, candidate.getFlatParameters(), stackTrace);
+        currentStatus.put(candidate.getIndex(), newStatus);
+
+        return newStatus;
+    }
+
+    /**
+     * Process returned task (either completed or failed
+     */
+    private void processReturnedTask(Future<OptimizationResult> future) {
+        long currentTime = System.currentTimeMillis();
+        OptimizationResult result;
+        try {
+            result = future.get(100, TimeUnit.MILLISECONDS);
+        } catch (InterruptedException e) {
+            throw new RuntimeException("Unexpected InterruptedException thrown for task", e);
+        } catch (ExecutionException e) {
+            //Note that most of the time, an OptimizationResult is returned even for an exception
+            //This is just to handle any that are missed there (or, by implementations that don't properly do this)
+            log.warn("Task failed", e);
+
+            numCandidatesFailed.getAndIncrement();
+            return;
+        } catch (TimeoutException e) {
+            throw new RuntimeException(e); //TODO
+        }
+
+        //Update internal status:
+        CandidateInfo status = currentStatus.get(result.getIndex());
+        CandidateInfo newStatus = new CandidateInfo(result.getIndex(), result.getCandidateInfo().getCandidateStatus(),
+                result.getScore(), status.getCreatedTime(), result.getCandidateInfo().getStartTime(),
+                currentTime, status.getFlatParams(), result.getCandidateInfo().getExceptionStackTrace());
+        currentStatus.put(result.getIndex(), newStatus);
+
+        //Listeners (on complete, etc) should be executed in underlying task
+
+
+        if (result.getCandidateInfo().getCandidateStatus() == CandidateStatus.Failed) {
+            log.info("Task {} failed during execution: {}", result.getIndex(), result.getCandidateInfo().getExceptionStackTrace());
+            numCandidatesFailed.getAndIncrement();
+        } else {
+
+            //Report completion to candidate generator
+            config.getCandidateGenerator().reportResults(result);
+
+            Double score = result.getScore();
+            log.info("Completed task {}, score = {}", result.getIndex(), result.getScore());
+
+            boolean minimize = config.getScoreFunction().minimize();
+            if (score != null && (bestScore == null
+                    || ((minimize && score < bestScore) || (!minimize && score > bestScore)))) {
+                if (bestScore == null) {
+                    log.info("New best score: {} (first completed model)", score);
+                } else {
+                    int idx = result.getIndex();
+                    int lastBestIdx = bestScoreCandidateIndex.get();
+                    log.info("New best score: {}, model {} (prev={}, model {})", score, idx, bestScore, lastBestIdx);
+                }
+                bestScore = score;
+                bestScoreTime = System.currentTimeMillis();
+                bestScoreCandidateIndex.set(result.getIndex());
+            }
+            numCandidatesCompleted.getAndIncrement();
+
+            //Model saving is done in the optimization tasks, to avoid CUDA threading issues
+            ResultReference resultReference = result.getResultReference();
+
+            if (resultReference != null)
+                allResults.add(resultReference);
+        }
+    }
+
+    @Override
+    public int numCandidatesTotal() {
+        return totalCandidateCount.get();
+    }
+
+    @Override
+    public int numCandidatesCompleted() {
+        return numCandidatesCompleted.get();
+    }
+
+    @Override
+    public int numCandidatesFailed() {
+        return numCandidatesFailed.get();
+    }
+
+    @Override
+    public int numCandidatesQueued() {
+        return queuedFutures.size();
+    }
+
+    @Override
+    public Double bestScore() {
+        return bestScore;
+    }
+
+    @Override
+    public Long bestScoreTime() {
+        return bestScoreTime;
+    }
+
+    @Override
+    public int bestScoreCandidateIndex() {
+        return bestScoreCandidateIndex.get();
+    }
+
+    @Override
+    public List<ResultReference> getResults() {
+        return new ArrayList<>(allResults);
+    }
+
+    @Override
+    public OptimizationConfiguration getConfiguration() {
+        return config;
+    }
+
+
+    @Override
+    public void addListeners(StatusListener... listeners) {
+        for (StatusListener l : listeners) {
+            if (!statusListeners.contains(l)) {
+                statusListeners.add(l);
+            }
+        }
+    }
+
+    @Override
+    public void removeListeners(StatusListener... listeners) {
+        for (StatusListener l : listeners) {
+            if (statusListeners.contains(l)) {
+                statusListeners.remove(l);
+            }
+        }
+    }
+
+    @Override
+    public void removeAllListeners() {
+        statusListeners.clear();
+    }
+
+    @Override
+    public List<CandidateInfo> getCandidateStatus() {
+        List<CandidateInfo> list = new ArrayList<>();
+        list.addAll(currentStatus.values());
+        return list;
+    }
+
+    private boolean terminate() {
+        for (TerminationCondition c : config.getTerminationConditions()) {
+            if (c.terminate(this)) {
+                log.info("BaseOptimizationRunner global termination condition hit: {}", c);
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @AllArgsConstructor
+    @Data
+    private class FutureDetails {
+        private final Future<OptimizationResult> future;
+        private final long startTime;
+        private final int index;
+    }
+
+    @AllArgsConstructor
+    private class OnCompletionListener implements Runnable {
+        private Future<OptimizationResult> future;
+
+        @Override
+        public void run() {
+            completedFutures.add(future);
+        }
+    }
+
+
+    protected abstract int maxConcurrentTasks();
+
+    @Deprecated
+    protected abstract ListenableFuture<OptimizationResult> execute(Candidate candidate, DataProvider dataProvider,
+                                                                    ScoreFunction scoreFunction);
+    @Deprecated
+    protected abstract List<ListenableFuture<OptimizationResult>> execute(List<Candidate> candidates,
+                                                                          DataProvider dataProvider, ScoreFunction scoreFunction);
+
+    protected abstract ListenableFuture<OptimizationResult> execute(Candidate candidate, Class<? extends DataSource> dataSource,
+                                                                    Properties dataSourceProperties, ScoreFunction scoreFunction);
+
+    protected abstract List<ListenableFuture<OptimizationResult>> execute(List<Candidate> candidates, Class<? extends DataSource> dataSource,
+                                                                          Properties dataSourceProperties, ScoreFunction scoreFunction);
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/runner/CandidateInfo.java

@@ -0,0 +1,41 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.runner;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+
+/**
+ * Simple helper class to store status of a candidate that is/has been/will be executed
+ */
+@AllArgsConstructor
+@Data
+public class CandidateInfo {
+
+    public CandidateInfo() {
+        //No arg constructor for Jackson
+    }
+
+    private int index;
+    private CandidateStatus candidateStatus;
+    private Double score;
+    private long createdTime;
+    private Long startTime;
+    private Long endTime;
+    private double[] flatParams; //Same as parameters in Candidate class
+    private String exceptionStackTrace;
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/runner/CandidateStatus.java

@@ -0,0 +1,24 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.runner;
+
+/**
+ * Status for candidates
+ */
+public enum CandidateStatus {
+    Created, Running, Complete, Failed, Cancelled
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/runner/IOptimizationRunner.java

@@ -0,0 +1,67 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.runner;
+
+import org.deeplearning4j.arbiter.optimize.api.saving.ResultReference;
+import org.deeplearning4j.arbiter.optimize.config.OptimizationConfiguration;
+import org.deeplearning4j.arbiter.optimize.runner.listener.StatusListener;
+import org.nd4j.shade.jackson.annotation.JsonTypeInfo;
+
+import java.util.List;
+
+@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@class")
+public interface IOptimizationRunner {
+
+    void execute();
+
+    /** Total number of candidates: created (scheduled), completed and failed */
+    int numCandidatesTotal();
+
+    int numCandidatesCompleted();
+
+    int numCandidatesFailed();
+
+    /** Number of candidates running or queued */
+    int numCandidatesQueued();
+
+    /** Best score found so far */
+    Double bestScore();
+
+    /** Time that the best score was found at, or 0 if no jobs have completed successfully */
+    Long bestScoreTime();
+
+    /** Index of the best scoring candidate, or -1 if no candidate has scored yet*/
+    int bestScoreCandidateIndex();
+
+    List<ResultReference> getResults();
+
+    OptimizationConfiguration getConfiguration();
+
+    void addListeners(StatusListener... listeners);
+
+    void removeListeners(StatusListener... listeners);
+
+    void removeAllListeners();
+
+    List<CandidateInfo> getCandidateStatus();
+
+    /**
+     * @param awaitCompletion If true: await completion of currently scheduled tasks. If false: shutdown immediately,
+     *                        cancelling any currently executing tasks
+     */
+    void shutdown(boolean awaitCompletion);
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/runner/LocalOptimizationRunner.java

@@ -0,0 +1,150 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.runner;
+
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.ListeningExecutorService;
+import com.google.common.util.concurrent.MoreExecutors;
+import lombok.Setter;
+import org.deeplearning4j.arbiter.optimize.api.*;
+import org.deeplearning4j.arbiter.optimize.api.data.DataProvider;
+import org.deeplearning4j.arbiter.optimize.api.data.DataSource;
+import org.deeplearning4j.arbiter.optimize.api.score.ScoreFunction;
+import org.deeplearning4j.arbiter.optimize.config.OptimizationConfiguration;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Properties;
+import java.util.concurrent.*;
+import java.util.concurrent.atomic.AtomicLong;
+
+/**
+ * LocalOptimizationRunner: execute hyperparameter optimization
+ * locally (on current machine, in current JVM).
+ *
+ * @author Alex Black
+ */
+public class LocalOptimizationRunner extends BaseOptimizationRunner {
+
+    public static final int DEFAULT_MAX_CONCURRENT_TASKS = 1;
+
+    private final int maxConcurrentTasks;
+
+    private TaskCreator taskCreator;
+    private ListeningExecutorService executor;
+    @Setter
+    private long shutdownMaxWaitMS = 2L * 24 * 60 * 60 * 1000;
+
+    public LocalOptimizationRunner(OptimizationConfiguration config){
+        this(config, null);
+    }
+
+    public LocalOptimizationRunner(OptimizationConfiguration config, TaskCreator taskCreator) {
+        this(DEFAULT_MAX_CONCURRENT_TASKS, config, taskCreator);
+    }
+
+    public LocalOptimizationRunner(int maxConcurrentTasks, OptimizationConfiguration config){
+        this(maxConcurrentTasks, config, null);
+    }
+
+    public LocalOptimizationRunner(int maxConcurrentTasks, OptimizationConfiguration config, TaskCreator taskCreator) {
+        super(config);
+        if (maxConcurrentTasks <= 0)
+            throw new IllegalArgumentException("maxConcurrentTasks must be > 0 (got: " + maxConcurrentTasks + ")");
+        this.maxConcurrentTasks = maxConcurrentTasks;
+
+        if(taskCreator == null){
+            Class<? extends ParameterSpace> psClass = config.getCandidateGenerator().getParameterSpace().getClass();
+            taskCreator = TaskCreatorProvider.defaultTaskCreatorFor(psClass);
+            if(taskCreator == null){
+                throw new IllegalStateException("No TaskCreator was provided and a default TaskCreator cannot be " +
+                        "inferred for ParameterSpace class " + psClass.getName() + ". Please provide a TaskCreator " +
+                        "via the LocalOptimizationRunner constructor");
+            }
+        }
+
+        this.taskCreator = taskCreator;
+
+        ExecutorService exec = Executors.newFixedThreadPool(maxConcurrentTasks, new ThreadFactory() {
+            private AtomicLong counter = new AtomicLong(0);
+
+            @Override
+            public Thread newThread(Runnable r) {
+                Thread t = Executors.defaultThreadFactory().newThread(r);
+                t.setDaemon(true);
+                t.setName("LocalCandidateExecutor-" + counter.getAndIncrement());
+                return t;
+            }
+        });
+        executor = MoreExecutors.listeningDecorator(exec);
+
+        init();
+    }
+
+    @Override
+    protected int maxConcurrentTasks() {
+        return maxConcurrentTasks;
+    }
+
+    @Override
+    protected ListenableFuture<OptimizationResult> execute(Candidate candidate, DataProvider dataProvider,
+                    ScoreFunction scoreFunction) {
+        return execute(Collections.singletonList(candidate), dataProvider, scoreFunction).get(0);
+    }
+
+    @Override
+    protected List<ListenableFuture<OptimizationResult>> execute(List<Candidate> candidates, DataProvider dataProvider,
+                    ScoreFunction scoreFunction) {
+        List<ListenableFuture<OptimizationResult>> list = new ArrayList<>(candidates.size());
+        for (Candidate candidate : candidates) {
+            Callable<OptimizationResult> task =
+                            taskCreator.create(candidate, dataProvider, scoreFunction, statusListeners, this);
+            list.add(executor.submit(task));
+        }
+        return list;
+    }
+
+    @Override
+    protected ListenableFuture<OptimizationResult> execute(Candidate candidate, Class<? extends DataSource> dataSource, Properties dataSourceProperties, ScoreFunction scoreFunction) {
+        return execute(Collections.singletonList(candidate), dataSource, dataSourceProperties, scoreFunction).get(0);
+    }
+
+    @Override
+    protected List<ListenableFuture<OptimizationResult>> execute(List<Candidate> candidates, Class<? extends DataSource> dataSource, Properties dataSourceProperties, ScoreFunction scoreFunction) {
+        List<ListenableFuture<OptimizationResult>> list = new ArrayList<>(candidates.size());
+        for (Candidate candidate : candidates) {
+            Callable<OptimizationResult> task = taskCreator.create(candidate, dataSource, dataSourceProperties, scoreFunction, statusListeners, this);
+            list.add(executor.submit(task));
+        }
+        return list;
+    }
+
+    @Override
+    public void shutdown(boolean awaitTermination) {
+        if(awaitTermination){
+            try {
+                executor.shutdown();
+                executor.awaitTermination(shutdownMaxWaitMS, TimeUnit.MILLISECONDS);
+            } catch (InterruptedException e){
+                throw new RuntimeException(e);
+            }
+        } else {
+            executor.shutdownNow();
+        }
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/runner/listener/BaseStatusListener.java

@@ -0,0 +1,54 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.runner.listener;
+
+import org.deeplearning4j.arbiter.optimize.api.OptimizationResult;
+import org.deeplearning4j.arbiter.optimize.runner.CandidateInfo;
+import org.deeplearning4j.arbiter.optimize.runner.IOptimizationRunner;
+
+/**
+ * BaseStatusListener: implements all methods of {@link StatusListener} as no-op.
+ * Users can extend this and override only the methods actually required
+ *
+ * @author Alex Black
+ */
+public abstract class BaseStatusListener implements StatusListener{
+    @Override
+    public void onInitialization(IOptimizationRunner runner) {
+        //No op
+    }
+
+    @Override
+    public void onShutdown(IOptimizationRunner runner) {
+        //No op
+    }
+
+    @Override
+    public void onRunnerStatusChange(IOptimizationRunner runner) {
+        //No op
+    }
+
+    @Override
+    public void onCandidateStatusChange(CandidateInfo candidateInfo, IOptimizationRunner runner, OptimizationResult result) {
+        //No op
+    }
+
+    @Override
+    public void onCandidateIteration(CandidateInfo candidateInfo, Object candidate, int iteration) {
+        //No op
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/runner/listener/StatusChangeType.java

@@ -0,0 +1,26 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.runner.listener;
+
+/**
+ * Created by Alex on 20/07/2017.
+ */
+public enum StatusChangeType {
+
+    CandidateCompleted, CandidateFailed, CandidateNewScheduled, CandidateNewBestScore
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/runner/listener/StatusListener.java

@@ -0,0 +1,60 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.runner.listener;
+
+import org.deeplearning4j.arbiter.optimize.api.OptimizationResult;
+import org.deeplearning4j.arbiter.optimize.runner.CandidateInfo;
+import org.deeplearning4j.arbiter.optimize.runner.IOptimizationRunner;
+
+/**
+ * The status Listener interface is used to inspect/track the status of execution, both for individual candidates,
+ * and for the optimisation runner overall.
+ *
+ * @author Alex Black
+ */
+public interface StatusListener {
+
+    /** Called when optimization runner starts execution */
+    void onInitialization(IOptimizationRunner runner);
+
+    /** Called when optimization runner terminates */
+    void onShutdown(IOptimizationRunner runner);
+
+    /** Called when any of the summary stats change, for the optimization runner:
+     * number scheduled, number completed, number failed, best score, etc. */
+    void onRunnerStatusChange(IOptimizationRunner runner);
+
+    /**
+     * Called when the status of the candidate is change. For example created, completed, failed.
+     *
+     * @param candidateInfo Candidate information
+     * @param runner        Optimisation runner calling this method
+     * @param result        Optimisation result. Maybe null.
+     */
+    void onCandidateStatusChange(CandidateInfo candidateInfo, IOptimizationRunner runner, OptimizationResult result);
+
+    /**
+     *  This method may be called by tasks as they are executing. The intent of this method is to report partial results,
+     *  such as different stages of learning, or scores/evaluations so far
+     *
+     * @param candidateInfo Candidate information
+     * @param candidate     Current candidate value/configuration
+     * @param iteration     Current iteration number
+     */
+    void onCandidateIteration(CandidateInfo candidateInfo, Object candidate, int iteration);
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/runner/listener/impl/LoggingStatusListener.java

@@ -0,0 +1,57 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.runner.listener.impl;
+
+import lombok.extern.slf4j.Slf4j;
+import org.deeplearning4j.arbiter.optimize.api.OptimizationResult;
+import org.deeplearning4j.arbiter.optimize.runner.CandidateInfo;
+import org.deeplearning4j.arbiter.optimize.runner.IOptimizationRunner;
+import org.deeplearning4j.arbiter.optimize.runner.listener.StatusListener;
+
+/**
+ * Created by Alex on 20/07/2017.
+ */
+@Slf4j
+public class LoggingStatusListener implements StatusListener {
+
+
+    @Override
+    public void onInitialization(IOptimizationRunner runner) {
+        log.info("Optimization runner: initialized");
+    }
+
+    @Override
+    public void onShutdown(IOptimizationRunner runner) {
+        log.info("Optimization runner: shut down");
+    }
+
+    @Override
+    public void onRunnerStatusChange(IOptimizationRunner runner) {
+        log.info("Optimization runner: status change");
+    }
+
+    @Override
+    public void onCandidateStatusChange(CandidateInfo candidateInfo, IOptimizationRunner runner,
+                    OptimizationResult result) {
+        log.info("Candidate status change: {}", candidateInfo);
+    }
+
+    @Override
+    public void onCandidateIteration(CandidateInfo candidateInfo, Object candidate, int iteration) {
+        log.info("Candidate iteration #{} - {}", iteration, candidate);
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/serde/jackson/GenericDeserializer.java

@@ -0,0 +1,46 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.serde.jackson;
+
+import org.nd4j.shade.jackson.core.JsonParser;
+import org.nd4j.shade.jackson.databind.DeserializationContext;
+import org.nd4j.shade.jackson.databind.JsonDeserializer;
+import org.nd4j.shade.jackson.databind.JsonNode;
+import org.nd4j.shade.jackson.databind.ObjectMapper;
+
+import java.io.IOException;
+
+/**
+ * Created by Alex on 15/02/2017.
+ */
+public class GenericDeserializer extends JsonDeserializer<Object> {
+    @Override
+    public Object deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
+        JsonNode node = p.getCodec().readTree(p);
+        String className = node.get("@class").asText();
+        Class<?> c;
+        try {
+            c = Class.forName(className);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+
+        JsonNode valueNode = node.get("value");
+        Object o = new ObjectMapper().treeToValue(valueNode, c);
+        return o;
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/serde/jackson/GenericSerializer.java

@@ -0,0 +1,38 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.serde.jackson;
+
+import org.nd4j.shade.jackson.core.JsonGenerator;
+import org.nd4j.shade.jackson.core.JsonProcessingException;
+import org.nd4j.shade.jackson.databind.JsonSerializer;
+import org.nd4j.shade.jackson.databind.SerializerProvider;
+
+import java.io.IOException;
+
+/**
+ * Created by Alex on 15/02/2017.
+ */
+public class GenericSerializer extends JsonSerializer<Object> {
+    @Override
+    public void serialize(Object o, JsonGenerator j, SerializerProvider serializerProvider)
+                    throws IOException, JsonProcessingException {
+        j.writeStartObject();
+        j.writeStringField("@class", o.getClass().getName());
+        j.writeObjectField("value", o);
+        j.writeEndObject();
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/serde/jackson/IntegerDistributionDeserializer.java

@@ -0,0 +1,59 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.serde.jackson;
+
+import org.apache.commons.math3.distribution.*;
+import org.nd4j.shade.jackson.core.JsonParser;
+import org.nd4j.shade.jackson.databind.DeserializationContext;
+import org.nd4j.shade.jackson.databind.JsonDeserializer;
+import org.nd4j.shade.jackson.databind.JsonNode;
+
+import java.io.IOException;
+
+/**
+ * Custom Jackson deserializer for integer distributions
+ *
+ * @author Alex Black
+ */
+public class IntegerDistributionDeserializer extends JsonDeserializer<IntegerDistribution> {
+
+    @Override
+    public IntegerDistribution deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
+        JsonNode node = p.getCodec().readTree(p);
+        String simpleName = node.get("distribution").asText();
+
+        switch (simpleName) {
+            case "BinomialDistribution":
+                return new BinomialDistribution(node.get("trials").asInt(), node.get("p").asDouble());
+            case "GeometricDistribution":
+                return new GeometricDistribution(node.get("p").asDouble());
+            case "HypergeometricDistribution":
+                return new HypergeometricDistribution(node.get("populationSize").asInt(),
+                                node.get("numberOfSuccesses").asInt(), node.get("sampleSize").asInt());
+            case "PascalDistribution":
+                return new PascalDistribution(node.get("r").asInt(), node.get("p").asDouble());
+            case "PoissonDistribution":
+                return new PoissonDistribution(node.get("p").asDouble());
+            case "UniformIntegerDistribution":
+                return new UniformIntegerDistribution(node.get("lower").asInt(), node.get("upper").asInt());
+            case "ZipfDistribution":
+                return new ZipfDistribution(node.get("numElements").asInt(), node.get("exponent").asDouble());
+            default:
+                throw new RuntimeException("Unknown or not supported distribution: " + simpleName);
+        }
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/serde/jackson/IntegerDistributionSerializer.java

@@ -0,0 +1,74 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.serde.jackson;
+
+import org.apache.commons.math3.distribution.*;
+import org.nd4j.shade.jackson.core.JsonGenerator;
+import org.nd4j.shade.jackson.databind.JsonSerializer;
+import org.nd4j.shade.jackson.databind.SerializerProvider;
+
+import java.io.IOException;
+
+/**
+ * Custom Jackson serializer for integer distributions
+ *
+ * @author Alex Black
+ */
+public class IntegerDistributionSerializer extends JsonSerializer<IntegerDistribution> {
+    @Override
+    public void serialize(IntegerDistribution d, JsonGenerator j, SerializerProvider serializerProvider)
+                    throws IOException {
+        Class<?> c = d.getClass();
+        String s = c.getSimpleName();
+
+        j.writeStartObject();
+        j.writeStringField("distribution", s);
+
+        if (c == BinomialDistribution.class) {
+            BinomialDistribution bd = (BinomialDistribution) d;
+            j.writeNumberField("trials", bd.getNumberOfTrials());
+            j.writeNumberField("p", bd.getProbabilityOfSuccess());
+        } else if (c == GeometricDistribution.class) {
+            GeometricDistribution gd = (GeometricDistribution) d;
+            j.writeNumberField("p", gd.getProbabilityOfSuccess());
+        } else if (c == HypergeometricDistribution.class) {
+            HypergeometricDistribution hd = (HypergeometricDistribution) d;
+            j.writeNumberField("populationSize", hd.getPopulationSize());
+            j.writeNumberField("numberOfSuccesses", hd.getNumberOfSuccesses());
+            j.writeNumberField("sampleSize", hd.getSampleSize());
+        } else if (c == PascalDistribution.class) {
+            PascalDistribution pd = (PascalDistribution) d;
+            j.writeNumberField("r", pd.getNumberOfSuccesses());
+            j.writeNumberField("p", pd.getProbabilityOfSuccess());
+        } else if (c == PoissonDistribution.class) {
+            PoissonDistribution pd = (PoissonDistribution) d;
+            j.writeNumberField("p", pd.getMean());
+        } else if (c == UniformIntegerDistribution.class) {
+            UniformIntegerDistribution ud = (UniformIntegerDistribution) d;
+            j.writeNumberField("lower", ud.getSupportLowerBound());
+            j.writeNumberField("upper", ud.getSupportUpperBound());
+        } else if (c == ZipfDistribution.class) {
+            ZipfDistribution zd = (ZipfDistribution) d;
+            j.writeNumberField("numElements", zd.getNumberOfElements());
+            j.writeNumberField("exponent", zd.getExponent());
+        } else {
+            throw new UnsupportedOperationException("Unknown or not supported IntegerDistribution: " + c);
+        }
+
+        j.writeEndObject();
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/serde/jackson/JsonMapper.java

@@ -0,0 +1,74 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.serde.jackson;
+
+import org.nd4j.shade.jackson.annotation.JsonAutoDetect;
+import org.nd4j.shade.jackson.annotation.PropertyAccessor;
+import org.nd4j.shade.jackson.databind.DeserializationFeature;
+import org.nd4j.shade.jackson.databind.ObjectMapper;
+import org.nd4j.shade.jackson.databind.SerializationFeature;
+import org.nd4j.shade.jackson.dataformat.yaml.YAMLFactory;
+import org.nd4j.shade.jackson.datatype.joda.JodaModule;
+
+import java.util.Collections;
+import java.util.Map;
+
+/**
+ * Created by Alex on 16/11/2016.
+ */
+public class JsonMapper {
+
+    private static ObjectMapper mapper;
+    private static ObjectMapper yamlMapper;
+
+    static {
+        mapper = new ObjectMapper();
+        mapper.registerModule(new JodaModule());
+        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+        mapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
+        mapper.enable(SerializationFeature.INDENT_OUTPUT);
+        mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.NONE);
+        mapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);
+        yamlMapper = new ObjectMapper(new YAMLFactory());
+        mapper.registerModule(new JodaModule());
+        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+        mapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
+        mapper.enable(SerializationFeature.INDENT_OUTPUT);
+        mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.NONE);
+        mapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);
+    }
+
+    private JsonMapper() {}
+
+
+    /**
+     * Return the yaml mapper
+     * @return
+     */
+    public static ObjectMapper getYamlMapper() {
+        return yamlMapper;
+    }
+
+    /**
+     * Return a json mapper
+     * @return
+     */
+    public static ObjectMapper getMapper() {
+        return mapper;
+    }
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/serde/jackson/RealDistributionDeserializer.java

@@ -0,0 +1,78 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.serde.jackson;
+
+import org.apache.commons.math3.distribution.*;
+import org.deeplearning4j.arbiter.optimize.distribution.LogUniformDistribution;
+import org.nd4j.shade.jackson.core.JsonParser;
+import org.nd4j.shade.jackson.core.JsonProcessingException;
+import org.nd4j.shade.jackson.databind.DeserializationContext;
+import org.nd4j.shade.jackson.databind.JsonDeserializer;
+import org.nd4j.shade.jackson.databind.JsonNode;
+
+import java.io.IOException;
+
+/**
+ * Created by Alex on 14/02/2017.
+ */
+public class RealDistributionDeserializer extends JsonDeserializer<RealDistribution> {
+
+    @Override
+    public RealDistribution deserialize(JsonParser p, DeserializationContext ctxt)
+                    throws IOException, JsonProcessingException {
+        JsonNode node = p.getCodec().readTree(p);
+        String simpleName = node.get("distribution").asText();
+
+        switch (simpleName) {
+            case "BetaDistribution":
+                return new BetaDistribution(node.get("alpha").asDouble(), node.get("beta").asDouble());
+            case "CauchyDistribution":
+                return new CauchyDistribution(node.get("median").asDouble(), node.get("scale").asDouble());
+            case "ChiSquaredDistribution":
+                return new ChiSquaredDistribution(node.get("dof").asDouble());
+            case "ExponentialDistribution":
+                return new ExponentialDistribution(node.get("mean").asDouble());
+            case "FDistribution":
+                return new FDistribution(node.get("numeratorDof").asDouble(), node.get("denominatorDof").asDouble());
+            case "GammaDistribution":
+                return new GammaDistribution(node.get("shape").asDouble(), node.get("scale").asDouble());
+            case "LevyDistribution":
+                return new LevyDistribution(node.get("mu").asDouble(), node.get("c").asDouble());
+            case "LogNormalDistribution":
+                return new LogNormalDistribution(node.get("scale").asDouble(), node.get("shape").asDouble());
+            case "NormalDistribution":
+                return new NormalDistribution(node.get("mean").asDouble(), node.get("stdev").asDouble());
+            case "ParetoDistribution":
+                return new ParetoDistribution(node.get("scale").asDouble(), node.get("shape").asDouble());
+            case "TDistribution":
+                return new TDistribution(node.get("dof").asDouble());
+            case "TriangularDistribution":
+                return new TriangularDistribution(node.get("a").asDouble(), node.get("b").asDouble(),
+                                node.get("c").asDouble());
+            case "UniformRealDistribution":
+                return new UniformRealDistribution(node.get("lower").asDouble(), node.get("upper").asDouble());
+            case "WeibullDistribution":
+                return new WeibullDistribution(node.get("alpha").asDouble(), node.get("beta").asDouble());
+            case "LogUniformDistribution":
+                return new LogUniformDistribution(node.get("min").asDouble(), node.get("max").asDouble());
+            default:
+                throw new RuntimeException("Unknown or not supported distribution: " + simpleName);
+        }
+
+
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/serde/jackson/RealDistributionSerializer.java

@@ -0,0 +1,107 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.serde.jackson;
+
+import org.apache.commons.math3.distribution.*;
+import org.deeplearning4j.arbiter.optimize.distribution.LogUniformDistribution;
+import org.nd4j.shade.jackson.core.JsonGenerator;
+import org.nd4j.shade.jackson.databind.JsonSerializer;
+import org.nd4j.shade.jackson.databind.SerializerProvider;
+
+import java.io.IOException;
+
+/**
+ * Custom JSON serializer for Apache commons RealDistribution instances.
+ * The custom serializer is set up to use the built-in c
+ */
+public class RealDistributionSerializer extends JsonSerializer<RealDistribution> {
+
+    @Override
+    public void serialize(RealDistribution d, JsonGenerator j, SerializerProvider serializerProvider)
+                    throws IOException {
+        Class<?> c = d.getClass();
+        String s = c.getSimpleName();
+
+        j.writeStartObject();
+        j.writeStringField("distribution", s);
+
+
+        if (c == BetaDistribution.class) {
+            BetaDistribution bd = (BetaDistribution) d;
+            j.writeNumberField("alpha", bd.getAlpha());
+            j.writeNumberField("beta", bd.getBeta());
+        } else if (c == CauchyDistribution.class) {
+            CauchyDistribution cd = (CauchyDistribution) d;
+            j.writeNumberField("median", cd.getMedian());
+            j.writeNumberField("scale", cd.getScale());
+        } else if (c == ChiSquaredDistribution.class) {
+            ChiSquaredDistribution cd = (ChiSquaredDistribution) d;
+            j.writeNumberField("dof", cd.getDegreesOfFreedom());
+        } else if (c == ExponentialDistribution.class) {
+            ExponentialDistribution ed = (ExponentialDistribution) d;
+            j.writeNumberField("mean", ed.getMean());
+        } else if (c == FDistribution.class) {
+            FDistribution fd = (FDistribution) d;
+            j.writeNumberField("numeratorDof", fd.getNumeratorDegreesOfFreedom());
+            j.writeNumberField("denominatorDof", fd.getDenominatorDegreesOfFreedom());
+        } else if (c == GammaDistribution.class) {
+            GammaDistribution gd = (GammaDistribution) d;
+            j.writeNumberField("shape", gd.getShape());
+            j.writeNumberField("scale", gd.getScale());
+        } else if (c == LevyDistribution.class) {
+            LevyDistribution ld = (LevyDistribution) d;
+            j.writeNumberField("mu", ld.getLocation());
+            j.writeNumberField("c", ld.getScale());
+        } else if (c == LogNormalDistribution.class) {
+            LogNormalDistribution ln = (LogNormalDistribution) d;
+            j.writeNumberField("scale", ln.getScale());
+            j.writeNumberField("shape", ln.getShape());
+        } else if (c == NormalDistribution.class) {
+            NormalDistribution nd = (NormalDistribution) d;
+            j.writeNumberField("mean", nd.getMean());
+            j.writeNumberField("stdev", nd.getStandardDeviation());
+        } else if (c == ParetoDistribution.class) {
+            ParetoDistribution pd = (ParetoDistribution) d;
+            j.writeNumberField("scale", pd.getScale());
+            j.writeNumberField("shape", pd.getShape());
+        } else if (c == TDistribution.class) {
+            TDistribution td = (TDistribution) d;
+            j.writeNumberField("dof", td.getDegreesOfFreedom());
+        } else if (c == TriangularDistribution.class) {
+            TriangularDistribution td = (TriangularDistribution) d;
+            j.writeNumberField("a", td.getSupportLowerBound());
+            j.writeNumberField("b", td.getMode());
+            j.writeNumberField("c", td.getSupportUpperBound());
+        } else if (c == UniformRealDistribution.class) {
+            UniformRealDistribution u = (UniformRealDistribution) d;
+            j.writeNumberField("lower", u.getSupportLowerBound());
+            j.writeNumberField("upper", u.getSupportUpperBound());
+        } else if (c == WeibullDistribution.class) {
+            WeibullDistribution wb = (WeibullDistribution) d;
+            j.writeNumberField("alpha", wb.getShape());
+            j.writeNumberField("beta", wb.getScale());
+        } else if (c == LogUniformDistribution.class){
+            LogUniformDistribution lud = (LogUniformDistribution) d;
+            j.writeNumberField("min", lud.getMin());
+            j.writeNumberField("max", lud.getMax());
+        } else {
+            throw new UnsupportedOperationException("Unknown or not supported RealDistribution: " + d.getClass());
+        }
+
+        j.writeEndObject();
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/optimize/serde/jackson/YamlMapper.java

@@ -0,0 +1,51 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize.serde.jackson;
+
+import org.nd4j.shade.jackson.annotation.JsonAutoDetect;
+import org.nd4j.shade.jackson.annotation.PropertyAccessor;
+import org.nd4j.shade.jackson.databind.DeserializationFeature;
+import org.nd4j.shade.jackson.databind.ObjectMapper;
+import org.nd4j.shade.jackson.databind.SerializationFeature;
+import org.nd4j.shade.jackson.dataformat.yaml.YAMLFactory;
+import org.nd4j.shade.jackson.datatype.joda.JodaModule;
+
+/**
+ * Created by Alex on 16/11/2016.
+ */
+public class YamlMapper {
+
+    private static final ObjectMapper mapper;
+
+    static {
+        mapper = new ObjectMapper(new YAMLFactory());
+        mapper.registerModule(new JodaModule());
+        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+        mapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
+        mapper.enable(SerializationFeature.INDENT_OUTPUT);
+        mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.NONE);
+        mapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);
+    }
+
+
+    private YamlMapper() {}
+
+    public static ObjectMapper getMapper() {
+        return mapper;
+    }
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/util/ClassPathResource.java

@@ -0,0 +1,234 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.util;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.*;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
+
+/**
+ * Simple utility class used to get access to files at the classpath, or packed into jar.
+ * Based on Spring ClassPathResource implementation + jar internals access implemented.
+ *
+ *
+ * @author raver119@gmail.com
+ */
+public class ClassPathResource {
+
+    private String resourceName;
+
+    private static Logger log = LoggerFactory.getLogger(ClassPathResource.class);
+
+    /**
+     * Builds new ClassPathResource object
+     *
+     * @param resourceName String name of resource, to be retrieved
+     */
+    public ClassPathResource(String resourceName) {
+        if (resourceName == null)
+            throw new IllegalStateException("Resource name can't be null");
+        this.resourceName = resourceName;
+    }
+
+    /**
+     *  Returns URL of the requested resource
+     *
+     * @return URL of the resource, if it's available in current Jar
+     */
+    private URL getUrl() {
+        ClassLoader loader = null;
+        try {
+            loader = Thread.currentThread().getContextClassLoader();
+        } catch (Exception e) {
+            // do nothing
+        }
+
+        if (loader == null) {
+            loader = ClassPathResource.class.getClassLoader();
+        }
+
+        URL url = loader.getResource(this.resourceName);
+        if (url == null) {
+            // try to check for mis-used starting slash
+            // TODO: see TODO below
+            if (this.resourceName.startsWith("/")) {
+                url = loader.getResource(this.resourceName.replaceFirst("[\\\\/]", ""));
+                if (url != null)
+                    return url;
+            } else {
+                // try to add slash, to make clear it's not an issue
+                // TODO: change this mechanic to actual path purifier
+                url = loader.getResource("/" + this.resourceName);
+                if (url != null)
+                    return url;
+            }
+            throw new IllegalStateException("Resource '" + this.resourceName + "' cannot be found.");
+        }
+        return url;
+    }
+
+    /**
+     * Returns requested ClassPathResource as File object
+     *
+     * Please note: if this method called from compiled jar, temporary file will be created to provide File access
+     *
+     * @return File requested at constructor call
+     * @throws FileNotFoundException
+     */
+    public File getFile() throws FileNotFoundException {
+        URL url = this.getUrl();
+
+        if (isJarURL(url)) {
+            /*
+                This is actually request for file, that's packed into jar. Probably the current one, but that doesn't matters.
+             */
+            try {
+                url = extractActualUrl(url);
+                File file = File.createTempFile("canova_temp", "file");
+                file.deleteOnExit();
+
+                ZipFile zipFile = new ZipFile(url.getFile());
+                ZipEntry entry = zipFile.getEntry(this.resourceName);
+                if (entry == null) {
+                    if (this.resourceName.startsWith("/")) {
+                        entry = zipFile.getEntry(this.resourceName.replaceFirst("/", ""));
+                        if (entry == null) {
+                            throw new FileNotFoundException("Resource " + this.resourceName + " not found");
+                        }
+                    } else
+                        throw new FileNotFoundException("Resource " + this.resourceName + " not found");
+                }
+
+                long size = entry.getSize();
+
+                InputStream stream = zipFile.getInputStream(entry);
+                FileOutputStream outputStream = new FileOutputStream(file);
+                byte[] array = new byte[1024];
+                int rd = 0;
+                long bytesRead = 0;
+                do {
+                    rd = stream.read(array);
+                    outputStream.write(array, 0, rd);
+                    bytesRead += rd;
+                } while (bytesRead < size);
+
+                outputStream.flush();
+                outputStream.close();
+
+                stream.close();
+                zipFile.close();
+
+                return file;
+            } catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+
+        } else {
+            /*
+                It's something in the actual underlying filesystem, so we can just go for it
+             */
+
+            try {
+                URI uri = new URI(url.toString().replaceAll(" ", "%20"));
+                return new File(uri.getSchemeSpecificPart());
+            } catch (URISyntaxException e) {
+                return new File(url.getFile());
+            }
+        }
+    }
+
+    /**
+     * Checks, if proposed URL is packed into archive.
+     *
+     * @param url URL to be checked
+     * @return True, if URL is archive entry, False otherwise
+     */
+    private boolean isJarURL(URL url) {
+        String protocol = url.getProtocol();
+        return "jar".equals(protocol) || "zip".equals(protocol) || "wsjar".equals(protocol)
+                        || "code-source".equals(protocol) && url.getPath().contains("!/");
+    }
+
+    /**
+     * Extracts parent Jar URL from original ClassPath entry URL.
+     *
+     * @param jarUrl Original URL of the resource
+     * @return URL of the Jar file, containing requested resource
+     * @throws MalformedURLException
+     */
+    private URL extractActualUrl(URL jarUrl) throws MalformedURLException {
+        String urlFile = jarUrl.getFile();
+        int separatorIndex = urlFile.indexOf("!/");
+        if (separatorIndex != -1) {
+            String jarFile = urlFile.substring(0, separatorIndex);
+
+            try {
+                return new URL(jarFile);
+            } catch (MalformedURLException var5) {
+                if (!jarFile.startsWith("/")) {
+                    jarFile = "/" + jarFile;
+                }
+
+                return new URL("file:" + jarFile);
+            }
+        } else {
+            return jarUrl;
+        }
+    }
+
+    /**
+     * Returns requested ClassPathResource as InputStream object
+     *
+     * @return File requested at constructor call
+     * @throws FileNotFoundException
+     */
+    public InputStream getInputStream() throws FileNotFoundException {
+        URL url = this.getUrl();
+        if (isJarURL(url)) {
+            try {
+                url = extractActualUrl(url);
+                ZipFile zipFile = new ZipFile(url.getFile());
+                ZipEntry entry = zipFile.getEntry(this.resourceName);
+
+                if (entry == null) {
+                    if (this.resourceName.startsWith("/")) {
+                        entry = zipFile.getEntry(this.resourceName.replaceFirst("/", ""));
+                        if (entry == null) {
+                            throw new FileNotFoundException("Resource " + this.resourceName + " not found");
+                        }
+                    } else
+                        throw new FileNotFoundException("Resource " + this.resourceName + " not found");
+                }
+
+                InputStream stream = zipFile.getInputStream(entry);
+                return stream;
+            } catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+        } else {
+            File srcFile = this.getFile();
+            return new FileInputStream(srcFile);
+        }
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/util/CollectionUtils.java

@@ -0,0 +1,49 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.util;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.List;
+
+public class CollectionUtils {
+
+    /**
+     * Count the number of unique values in a collection
+     */
+    public static int countUnique(Collection<?> collection) {
+        HashSet<Object> set = new HashSet<>(collection);
+        return set.size();
+    }
+
+    /**
+     * Returns a list containing only unique values in a collection
+     */
+    public static <T> List<T> getUnique(Collection<T> collection) {
+        HashSet<T> set = new HashSet<>();
+        List<T> out = new ArrayList<>();
+        for (T t : collection) {
+            if (!set.contains(t)) {
+                out.add(t);
+                set.add(t);
+            }
+        }
+        return out;
+    }
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/util/LeafUtils.java

@@ -0,0 +1,73 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.util;
+
+import org.deeplearning4j.arbiter.optimize.api.ParameterSpace;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Created by Alex on 29/06/2017.
+ */
+public class LeafUtils {
+
+    private LeafUtils() {}
+
+    /**
+     * Returns a list of unique objects, not using the .equals() method, but rather using ==
+     *
+     * @param allLeaves Leaf values to process
+     * @return A list of unique parameter space values
+     */
+    public static List<ParameterSpace> getUniqueObjects(List<ParameterSpace> allLeaves) {
+        List<ParameterSpace> unique = new ArrayList<>();
+        for (ParameterSpace p : allLeaves) {
+            //This isn't especially efficient, but small number of parameters in general means it's fine
+            boolean found = false;
+            for (ParameterSpace q : unique) {
+                if (p == q) {
+                    found = true;
+                }
+            }
+            if (!found) {
+                unique.add(p);
+            }
+        }
+
+        return unique;
+    }
+
+    /**
+     * Count the number of unique parameters in the specified leaf nodes
+     *
+     * @param allLeaves Leaf values to count the parameters fore
+     * @return Number of parameters for all unique objects
+     */
+    public static int countUniqueParameters(List<ParameterSpace> allLeaves) {
+        List<ParameterSpace> unique = getUniqueObjects(allLeaves);
+        int count = 0;
+        for (ParameterSpace ps : unique) {
+            if (!ps.isLeaf()) {
+                throw new IllegalStateException("Method should only be used with leaf nodes");
+            }
+            count += ps.numParameters();
+        }
+        return count;
+    }
+
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/util/ObjectUtils.java

@@ -0,0 +1,61 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.util;
+
+import java.util.Arrays;
+
+/**
+ * @author Alex Black
+ */
+public class ObjectUtils {
+
+    private ObjectUtils() {}
+
+    /**
+     * Get the string representation of the object. Arrays, including primitive arrays, are printed using
+     * Arrays.toString(...) methods.
+     *
+     * @param v Value to convert to a string
+     * @return String representation
+     */
+    public static String valueToString(Object v) {
+        if (v.getClass().isArray()) {
+            if (v.getClass().getComponentType().isPrimitive()) {
+                Class<?> c = v.getClass().getComponentType();
+                if (c == int.class) {
+                    return Arrays.toString((int[]) v);
+                } else if (c == double.class) {
+                    return Arrays.toString((double[]) v);
+                } else if (c == float.class) {
+                    return Arrays.toString((float[]) v);
+                } else if (c == long.class) {
+                    return Arrays.toString((long[]) v);
+                } else if (c == byte.class) {
+                    return Arrays.toString((byte[]) v);
+                } else if (c == short.class) {
+                    return Arrays.toString((short[]) v);
+                } else {
+                    return v.toString();
+                }
+            } else {
+                return Arrays.toString((Object[]) v);
+            }
+        } else {
+            return v.toString();
+        }
+    }
+}

arbiter/arbiter-core/src/main/java/org/deeplearning4j/arbiter/util/WebUtils.java

@@ -0,0 +1,47 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.util;
+
+import org.slf4j.Logger;
+
+import java.awt.*;
+import java.net.URI;
+
+/**
+ * Various utilities for webpages and dealing with browsers
+ */
+public class WebUtils {
+
+    public static void tryOpenBrowser(String path, Logger log) {
+        try {
+            WebUtils.openBrowser(new URI(path));
+        } catch (Exception e) {
+            log.error("Could not open browser", e);
+            System.out.println("Browser could not be launched automatically.\nUI path: " + path);
+        }
+    }
+
+    public static void openBrowser(URI uri) throws Exception {
+        if (Desktop.isDesktopSupported()) {
+            Desktop.getDesktop().browse(uri);
+        } else {
+            throw new UnsupportedOperationException(
+                            "Cannot open browser on this platform: Desktop.isDesktopSupported() == false");
+        }
+    }
+
+}

arbiter/arbiter-core/src/test/java/org/deeplearning4j/arbiter/optimize/BraninFunction.java

@@ -0,0 +1,156 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import org.deeplearning4j.arbiter.optimize.api.*;
+import org.deeplearning4j.arbiter.optimize.api.data.DataProvider;
+import org.deeplearning4j.arbiter.optimize.api.data.DataSource;
+import org.deeplearning4j.arbiter.optimize.api.score.ScoreFunction;
+import org.deeplearning4j.arbiter.optimize.parameter.continuous.ContinuousParameterSpace;
+import org.deeplearning4j.arbiter.optimize.runner.CandidateInfo;
+import org.deeplearning4j.arbiter.optimize.runner.CandidateStatus;
+import org.deeplearning4j.arbiter.optimize.runner.IOptimizationRunner;
+import org.deeplearning4j.arbiter.optimize.runner.listener.StatusListener;
+
+import java.io.Serializable;
+import java.util.*;
+import java.util.concurrent.Callable;
+
+public class BraninFunction {
+    public static class BraninSpace extends AbstractParameterSpace<BraninConfig> {
+        private int[] indices;
+        private ParameterSpace<Double> first = new ContinuousParameterSpace(-5, 10);
+        private ParameterSpace<Double> second = new ContinuousParameterSpace(0, 15);
+
+        @Override
+        public BraninConfig getValue(double[] parameterValues) {
+            double f = first.getValue(parameterValues);
+            double s = second.getValue(parameterValues);
+            return new BraninConfig(f, s); //-5 to +10 and 0 to 15
+        }
+
+        @Override
+        public int numParameters() {
+            return 2;
+        }
+
+        @Override
+        public List<ParameterSpace> collectLeaves() {
+            List<ParameterSpace> list = new ArrayList<>();
+            list.addAll(first.collectLeaves());
+            list.addAll(second.collectLeaves());
+            return list;
+        }
+
+        @Override
+        public boolean isLeaf() {
+            return false;
+        }
+
+        @Override
+        public void setIndices(int... indices) {
+            throw new UnsupportedOperationException();
+        }
+    }
+
+    @AllArgsConstructor
+    @Data
+    public static class BraninConfig implements Serializable {
+        private double x1;
+        private double x2;
+    }
+
+    public static class BraninScoreFunction implements ScoreFunction {
+        private static final double a = 1.0;
+        private static final double b = 5.1 / (4.0 * Math.PI * Math.PI);
+        private static final double c = 5.0 / Math.PI;
+        private static final double r = 6.0;
+        private static final double s = 10.0;
+        private static final double t = 1.0 / (8.0 * Math.PI);
+
+        @Override
+        public double score(Object m, DataProvider data, Map<String, Object> dataParameters) {
+            BraninConfig model = (BraninConfig) m;
+            double x1 = model.getX1();
+            double x2 = model.getX2();
+
+            return a * Math.pow(x2 - b * x1 * x1 + c * x1 - r, 2.0) + s * (1 - t) * Math.cos(x1) + s;
+        }
+
+        @Override
+        public double score(Object model, Class<? extends DataSource> dataSource, Properties dataSourceProperties) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public boolean minimize() {
+            return true;
+        }
+
+        @Override
+        public List<Class<?>> getSupportedModelTypes() {
+            return Collections.<Class<?>>singletonList(BraninConfig.class);
+        }
+
+        @Override
+        public List<Class<?>> getSupportedDataTypes() {
+            return Collections.<Class<?>>singletonList(Object.class);
+        }
+    }
+
+    public static class BraninTaskCreator implements TaskCreator {
+        @Override
+        public Callable<OptimizationResult> create(final Candidate c, DataProvider dataProvider,
+                        final ScoreFunction scoreFunction, final List<StatusListener> statusListeners,
+                        IOptimizationRunner runner) {
+
+            return new Callable<OptimizationResult>() {
+                @Override
+                public OptimizationResult call() throws Exception {
+
+                    BraninConfig candidate = (BraninConfig) c.getValue();
+
+                    double score = scoreFunction.score(candidate, null, (Map) null);
+                    System.out.println(candidate.getX1() + "\t" + candidate.getX2() + "\t" + score);
+
+                    Thread.sleep(20);
+
+                    if (statusListeners != null) {
+                        for (StatusListener sl : statusListeners) {
+                            sl.onCandidateIteration(null, null, 0);
+                        }
+                    }
+
+                    CandidateInfo ci = new CandidateInfo(-1, CandidateStatus.Complete, score,
+                                    System.currentTimeMillis(), null, null, null, null);
+
+                    return new OptimizationResult(c, score, c.getIndex(), null, ci, null);
+                }
+            };
+        }
+
+        @Override
+        public Callable<OptimizationResult> create(Candidate candidate, Class<? extends DataSource> dataSource,
+                        Properties dataSourceProperties, ScoreFunction scoreFunction,
+                        List<StatusListener> statusListeners, IOptimizationRunner runner) {
+            throw new UnsupportedOperationException();
+        }
+    }
+
+}

arbiter/arbiter-core/src/test/java/org/deeplearning4j/arbiter/optimize/TestGeneticSearch.java

@@ -0,0 +1,117 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2019 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.deeplearning4j.arbiter.optimize;
+
+import org.deeplearning4j.arbiter.optimize.api.CandidateGenerator;
+import org.deeplearning4j.arbiter.optimize.api.score.ScoreFunction;
+import org.deeplearning4j.arbiter.optimize.api.termination.MaxCandidatesCondition;
+import org.deeplearning4j.arbiter.optimize.api.termination.TerminationCondition;
+import org.deeplearning4j.arbiter.optimize.config.OptimizationConfiguration;
+import org.deeplearning4j.arbiter.optimize.generator.GeneticSearchCandidateGenerator;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.exceptions.GeneticGenerationException;
+import org.deeplearning4j.arbiter.optimize.generator.genetic.selection.SelectionOperator;
+import org.deeplearning4j.arbiter.optimize.runner.CandidateInfo;
+import org.deeplearning4j.arbiter.optimize.runner.CandidateStatus;
+import org.deeplearning4j.arbiter.optimize.runner.IOptimizationRunner;
+import org.deeplearning4j.arbiter.optimize.runner.LocalOptimizationRunner;
+import org.deeplearning4j.arbiter.optimize.runner.listener.impl.LoggingStatusListener;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TestGeneticSearch {
+    public class TestSelectionOperator extends SelectionOperator {
+
+        @Override
+        public double[] buildNextGenes() {
+            throw new GeneticGenerationException("Forced exception to test exception handling.");
+        }
+    }
+
+    public class TestTerminationCondition implements TerminationCondition {
+
+        public boolean hasAFailedCandidate = false;
+        public int evalCount = 0;
+
+        @Override
+        public void initialize(IOptimizationRunner optimizationRunner) {}
+
+        @Override
+        public boolean terminate(IOptimizationRunner optimizationRunner) {
+            if (++evalCount == 50) {
+                // Generator did not handle GeneticGenerationException
+                return true;
+            }
+
+            for (CandidateInfo candidateInfo : optimizationRunner.getCandidateStatus()) {
+                if (candidateInfo.getCandidateStatus() == CandidateStatus.Failed) {
+                    hasAFailedCandidate = true;
+                    return true;
+                }
+            }
+
+            return false;
+        }
+    }
+
+    @Test
+    public void GeneticSearchCandidateGenerator_getCandidate_ShouldGenerateCandidates() throws Exception {
+
+        ScoreFunction scoreFunction = new BraninFunction.BraninScoreFunction();
+
+        //Define configuration:
+        CandidateGenerator candidateGenerator =
+                        new GeneticSearchCandidateGenerator.Builder(new BraninFunction.BraninSpace(), scoreFunction)
+                                        .build();
+
+        TestTerminationCondition testTerminationCondition = new TestTerminationCondition();
+        OptimizationConfiguration configuration = new OptimizationConfiguration.Builder()
+                        .candidateGenerator(candidateGenerator).scoreFunction(scoreFunction)
+                        .terminationConditions(new MaxCandidatesCondition(50), testTerminationCondition).build();
+
+        IOptimizationRunner runner = new LocalOptimizationRunner(configuration, new BraninFunction.BraninTaskCreator());
+
+        runner.addListeners(new LoggingStatusListener());
+        runner.execute();
+
+        Assert.assertFalse(testTerminationCondition.hasAFailedCandidate);
+    }
+
+    @Test
+    public void GeneticSearchCandidateGenerator_getCandidate_GeneticExceptionShouldMarkCandidateAsFailed() {
+
+        ScoreFunction scoreFunction = new BraninFunction.BraninScoreFunction();
+
+        //Define configuration:
+        CandidateGenerator candidateGenerator =
+                        new GeneticSearchCandidateGenerator.Builder(new BraninFunction.BraninSpace(), scoreFunction)
+                                        .selectionOperator(new TestSelectionOperator()).build();
+
+        TestTerminationCondition testTerminationCondition = new TestTerminationCondition();
+
+        OptimizationConfiguration configuration = new OptimizationConfiguration.Builder()
+                        .candidateGenerator(candidateGenerator).scoreFunction(scoreFunction)
+                        .terminationConditions(testTerminationCondition).build();
+
+        IOptimizationRunner runner = new LocalOptimizationRunner(configuration, new BraninFunction.BraninTaskCreator());
+
+        runner.addListeners(new LoggingStatusListener());
+        runner.execute();
+
+        Assert.assertTrue(testTerminationCondition.hasAFailedCandidate);
+    }
+
+}