org.deeplearning4j.earlystopping.termination.ScoreImprovementEpochTerminationCondition Maven / Gradle / Ivy
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* 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
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* under the License.
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* SPDX-License-Identifier: Apache-2.0
******************************************************************************/
package org.deeplearning4j.earlystopping.termination;
import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import org.nd4j.shade.jackson.annotation.JsonProperty;
/**
* Terminate training if best model score does not improve for N epochs
*/
@Slf4j
@Data
public class ScoreImprovementEpochTerminationCondition implements EpochTerminationCondition {
@JsonProperty
private int maxEpochsWithNoImprovement;
@JsonProperty
private int bestEpoch = -1;
@JsonProperty
private double bestScore;
@JsonProperty
private double minImprovement = 0.0;
public ScoreImprovementEpochTerminationCondition(int maxEpochsWithNoImprovement) {
this.maxEpochsWithNoImprovement = maxEpochsWithNoImprovement;
}
public ScoreImprovementEpochTerminationCondition(@JsonProperty("maxEpochsWithNoImprovement") int maxEpochsWithNoImprovement,
@JsonProperty("minImprovement") double minImprovement) {
this.maxEpochsWithNoImprovement = maxEpochsWithNoImprovement;
this.minImprovement = minImprovement;
}
@Override
public void initialize() {
bestEpoch = -1;
bestScore = Double.NaN;
}
@Override
public boolean terminate(int epochNum, double score, boolean minimize) {
if (bestEpoch == -1) {
bestEpoch = epochNum;
bestScore = score;
return false;
} else {
double improvement = (minimize ? bestScore - score : score - bestScore);
if (improvement > minImprovement) {
if (minImprovement > 0) {
log.info("Epoch with score greater than threshold * * *");
}
bestScore = score;
bestEpoch = epochNum;
return false;
}
return epochNum >= bestEpoch + maxEpochsWithNoImprovement;
}
}
@Override
public String toString() {
return "ScoreImprovementEpochTerminationCondition(maxEpochsWithNoImprovement=" + maxEpochsWithNoImprovement
+ ", minImprovement=" + minImprovement + ")";
}
}