cavis/libnd4j/include/ops/declarable/generic/random/multinomial.cpp

117 lines
5.0 KiB
C++

/*
* ******************************************************************************
* *
* *
* * 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.
* *
* * See the NOTICE file distributed with this work for additional
* * information regarding copyright ownership.
* * 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
* *****************************************************************************
*/
//
// @author Oleh Semeniv (oleg.semeniv@gmail.com)
//
#include <system/op_boilerplate.h>
#if NOT_EXCLUDED(OP_random_multinomial)
#include <ops/declarable/CustomOperations.h>
#include <helpers/RandomLauncher.h>
#include <ops/declarable/helpers/random.h>
namespace sd {
namespace ops {
///////////////////////
/**
* multinomial (categorical) random generator
* takes 2D ndarray with logits with shape [batch_size (N), num_classes (K)]
* and array with one scalar value of samples number, number of independent samples to draw for each experiment 1,N.
* represents the unnormalized log-probabilities for all classes.
* Int arguments: 0 - optional argument, corresponds to dimension with batch_size
* Int arguments: 1 - optional argument, integer type to use for the output. Default int64.
*/
// used https://en.wikipedia.org/wiki/Categorical_distribution
// methods: gumbel trick + softmax + argmax
CUSTOM_OP_IMPL(random_multinomial, 2, 1, false, 0, 0) {
auto input = INPUT_VARIABLE(0);
auto output = OUTPUT_NULLIFIED(0);
auto inputSamples = INPUT_VARIABLE(1);
REQUIRE_TRUE(!input->isEmpty(), 0, "RANDOM_MULTINOMIAL OP: Have to be provided at least one logits. ");
REQUIRE_TRUE(inputSamples->lengthOf() == 1, 0, "RANDOM_MULTINOMIAL OP: Have to be specified at least one sample,"
" but got no argumets instead.");
Nd4jLong numOfSamples = static_cast<Nd4jLong>(inputSamples->e<int>(0));
// do nothing if number of samples = 0
if (0 == numOfSamples)
return Status::OK();
REQUIRE_TRUE(numOfSamples > 0, 0, "RANDOM_MULTINOMIAL OP: Number of samples should be greater then 0, got %i. ", numOfSamples);
const int rank = input->rankOf();
REQUIRE_TRUE(rank == 2, 0, "RANDOM_MULTINOMIAL OP: Logits should be a matrix with rank = 2, but got instead rank = %i.", rank);
const int argSize = block.getIArguments()->size();
const int dimC = argSize > 0 ? (INT_ARG(0) >= 0 ? INT_ARG(0) : INT_ARG(0) + rank) : rank - 1;
auto dimA = (0 == dimC) ? 1 : 0;
if (1 == input->sizeAt(dimA)) {
*output = 0;
return Status::OK();
}
auto rng = block.randomGenerator();
helpers::fillRandomMultiNomial(block.launchContext(), rng, *input, *output, numOfSamples, dimC);
return Status::OK();
}
DECLARE_SHAPE_FN(random_multinomial) {
auto input = INPUT_VARIABLE(0);
auto inputSamples = INPUT_VARIABLE(1);
REQUIRE_TRUE(inputSamples->lengthOf() == 1, 0, "RANDOM_MULTINOMIAL OP: Have to be specified at least one sample,"
" but got no argumets instead.");
Nd4jLong numOfSamples = static_cast<Nd4jLong>(inputSamples->e<int>(0));
REQUIRE_TRUE(numOfSamples > 0, 0, "RANDOM_MULTINOMIAL OP: Number of samples should be greater then 0, got %i. ", numOfSamples);
const int rank = input->rankOf();
REQUIRE_TRUE(rank == 2, 0, "RANDOM_MULTINOMIAL OP: Logits should be a matrix with rank = 2, but got instead rank = %i.", rank);
const int argSize = block.getIArguments()->size();
const int dimC = argSize > 0 ? (INT_ARG(0) >= 0 ? INT_ARG(0) : INT_ARG(0) + rank) : rank - 1;
auto nShape = input->getShapeAsVector();
auto dimA = (0 == dimC) ? 1 : 0;
nShape[dimA] = numOfSamples;
DataType nType = (argSize > 1) ? ( INT_ARG(1) >= 0 ? static_cast<DataType>(INT_ARG(1)) : sd::DataType::INT64) : sd::DataType::INT64;
return SHAPELIST(ConstantShapeHelper::getInstance().createShapeInfo(nType, input->ordering(), nShape));
}
DECLARE_TYPES(random_multinomial) {
getOpDescriptor()
->setAllowedInputTypes(0, { ALL_FLOATS, ALL_INTS })
->setAllowedInputTypes(1, { sd::DataType::INT32 })
->setAllowedOutputTypes(0, { ALL_INDICES });
}
}
}
#endif