org.nd4j.linalg.learning.config.Sgd Maven / Gradle / Ivy
/*******************************************************************************
* 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.nd4j.linalg.learning.config;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.EqualsAndHashCode;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.learning.GradientUpdater;
import org.nd4j.linalg.learning.SgdUpdater;
import org.nd4j.linalg.schedule.ISchedule;
import org.nd4j.shade.jackson.annotation.JsonProperty;
/**
* SGD updater applies a learning rate only
* @author Adam Gibson
*/
@Data
@EqualsAndHashCode
@Builder(builderClassName = "Builder")
public class Sgd implements IUpdater {
public static final double DEFAULT_SGD_LR = 1e-3;
@lombok.Builder.Default private double learningRate = DEFAULT_SGD_LR;
private ISchedule learningRateSchedule;
public Sgd(){
this(DEFAULT_SGD_LR, null);
}
public Sgd(double learningRate){
this(learningRate, null);
}
public Sgd(ISchedule learningRateSchedule){
this(Double.NaN, learningRateSchedule);
}
private Sgd(@JsonProperty("learningRate") double learningRate,
@JsonProperty("learningRateSchedule") ISchedule learningRateSchedule){
this.learningRate = learningRate;
this.learningRateSchedule = learningRateSchedule;
}
@Override
public long stateSize(long numParams) {
return 0;
}
@Override
public GradientUpdater instantiate(INDArray viewArray, boolean initializeViewArray) {
if (viewArray != null) {
throw new IllegalStateException("View arrays are not supported/required for SGD updater");
}
return new SgdUpdater(this);
}
@Override
public Sgd clone() {
return new Sgd(learningRate, learningRateSchedule);
}
@Override
public double getLearningRate(int iteration, int epoch){
if(learningRateSchedule != null){
return learningRateSchedule.valueAt(iteration, epoch);
}
return learningRate;
}
@Override
public boolean hasLearningRate() {
return true;
}
@Override
public void setLrAndSchedule(double lr, ISchedule lrSchedule) {
this.learningRate = lr;
this.learningRateSchedule = lrSchedule;
}
//Partial builder implementation to give public no-arg constructor
public static class Builder {
public Builder(){ }
}
}