org.nd4j.linalg.learning.RmsPropUpdater Maven / Gradle / Ivy
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* * 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.
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* * See the NOTICE file distributed with this work for additional
* * information regarding copyright ownership.
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* * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* * SPDX-License-Identifier: Apache-2.0
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package org.nd4j.linalg.learning;
import lombok.Data;
import lombok.NonNull;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.api.shape.Shape;
import org.nd4j.linalg.factory.Nd4j;
import org.nd4j.linalg.learning.config.RmsProp;
import java.util.Collections;
import java.util.Map;
@Data
public class RmsPropUpdater implements GradientUpdater {
public static final String G_STATE = "G";
private final RmsProp config;
private INDArray lastGradient;
private char gradientReshapeOrder;
public RmsPropUpdater(RmsProp config) {
this.config = config;
}
@Override
public void setState(@NonNull Map stateMap, boolean initialize) {
if(!stateMap.containsKey(G_STATE) || stateMap.size() != 1){
throw new IllegalStateException("State map should contain only key [" + G_STATE + "] but has keys " + stateMap.keySet());
}
this.lastGradient = stateMap.get(G_STATE);
}
@Override
public Map getState() {
return Collections.singletonMap(G_STATE, this.lastGradient);
}
@Override
public void setStateViewArray(INDArray viewArray, long[] gradientShape, char gradientOrder, boolean initialize) {
if (!viewArray.isRowVectorOrScalar())
throw new IllegalArgumentException("Invalid input: expect row vector input");
if (initialize)
viewArray.assign(config.getEpsilon());
this.lastGradient = viewArray;
//Reshape to match the expected shape of the input gradient arrays
this.lastGradient = Shape.newShapeNoCopy(this.lastGradient, gradientShape, gradientOrder == 'f');
if (lastGradient == null)
throw new IllegalStateException("Could not correctly reshape gradient view array");
gradientReshapeOrder = gradientOrder;
}
@Override
public void applyUpdater(INDArray gradient, int iteration, int epoch) {
if (lastGradient == null)
throw new IllegalStateException("Updater has not been initialized with view state");
double learningRate = config.getLearningRate(iteration, epoch);
double rmsDecay = config.getRmsDecay();
double epsilon = config.getEpsilon();
// lr * gradient / (sqrt(cache) + 1e-8)
Nd4j.exec(new org.nd4j.linalg.api.ops.impl.updaters.RmsPropUpdater(gradient.reshape(lastGradient.shape()), lastGradient, learningRate, rmsDecay, epsilon));
}
}