cavis/rl4j/rl4j-core/src/main/java/org/deeplearning4j/rl4j/policy/DQNPolicy.java

/*******************************************************************************
 * 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.rl4j.policy;

import lombok.AllArgsConstructor;
import org.deeplearning4j.rl4j.learning.Learning;
import org.deeplearning4j.rl4j.network.dqn.DQN;
import org.deeplearning4j.rl4j.network.dqn.IDQN;
import org.deeplearning4j.rl4j.observation.Observation;
import org.deeplearning4j.rl4j.space.Encodable;
import org.nd4j.linalg.api.ndarray.INDArray;

import java.io.IOException;

/**
 * @author rubenfiszel (ruben.fiszel@epfl.ch) 7/18/16.
 *
 * DQN policy returns the action with the maximum Q-value as evaluated
 * by the dqn model
 */
@AllArgsConstructor
public class DQNPolicy<O extends Encodable> extends Policy<O, Integer> {

    final private IDQN dqn;

    public static <O extends Encodable> DQNPolicy<O> load(String path) throws IOException {
        return new DQNPolicy<O>(DQN.load(path));
    }

    public IDQN getNeuralNet() {
        return dqn;
    }

    @Override
    public Integer nextAction(Observation obs) {
        return nextAction(obs.getData());
    }

    public Integer nextAction(INDArray input) {
        INDArray output = dqn.output(input);
        return Learning.getMaxAction(output);
    }

    public void save(String filename) throws IOException {
        dqn.save(filename);
    }

}