org.nd4j.linalg.learning.config.IUpdater Maven / Gradle / Ivy
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* Copyright (c) 2015-2018 Skymind, Inc.
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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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package org.nd4j.linalg.learning.config;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.learning.GradientUpdater;
import org.nd4j.linalg.schedule.ISchedule;
import org.nd4j.shade.jackson.annotation.JsonAutoDetect;
import org.nd4j.shade.jackson.annotation.JsonInclude;
import org.nd4j.shade.jackson.annotation.JsonTypeInfo;
import java.io.Serializable;
/**
* IUpdater interface: used for configuration and instantiation of updaters - both built-in and custom.
* Note that the actual implementations for updaters are in {@link GradientUpdater}
*
* @author Alex Black
*/
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonAutoDetect(fieldVisibility = JsonAutoDetect.Visibility.ANY, getterVisibility = JsonAutoDetect.Visibility.NONE,
setterVisibility = JsonAutoDetect.Visibility.NONE)
@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@class")
public interface IUpdater extends Serializable, Cloneable {
/**
* Determine the updater state size for the given number of parameters. Usually a integer multiple (0,1 or 2)
* times the number of parameters in a layer.
*
* @param numParams Number of parameters
* @return Updater state size for the given number of parameters
*/
long stateSize(long numParams);
/**
* Create a new gradient updater
*
* @param viewArray The updater state size view away
* @param initializeViewArray If true: initialise the updater state
* @return
*/
GradientUpdater instantiate(INDArray viewArray, boolean initializeViewArray);
boolean equals(Object updater);
/**
* Clone the updater
*/
IUpdater clone();
/**
* Get the learning rate - if any - for the updater, at the specified iteration and epoch.
* Note that if no learning rate is applicable (AdaDelta, NoOp updaters etc) then Double.NaN should
* be return
*
* @param iteration Iteration at which to get the learning rate
* @param epoch Epoch at which to get the learning rate
* @return Learning rate, or Double.NaN if no learning rate is applicable for this updater
*/
double getLearningRate(int iteration, int epoch);
/**
* @return True if the updater has a learning rate hyperparameter, false otherwise
*/
boolean hasLearningRate();
/**
* Set the learning rate and schedule. Note: may throw an exception if {@link #hasLearningRate()} returns false.
* @param lr Learning rate to set (typically not used if LR schedule is non-null)
* @param lrSchedule Learning rate schedule to set (may be null)
*/
void setLrAndSchedule(double lr, ISchedule lrSchedule);
}