org.deeplearning4j.nn.gradient.Gradient 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.deeplearning4j.nn.gradient;
import org.nd4j.linalg.api.ndarray.INDArray;
import java.io.Serializable;
import java.util.List;
import java.util.Map;
/**
* Generic gradient
*
* @author Adam Gibson
*/
public interface Gradient extends Serializable {
/**
* Gradient look up table
*
* @return the gradient look up table
*/
Map gradientForVariable();
/**
* The full gradient as one flat vector
*
* @return
*/
INDArray gradient(List order);
/**
* The full gradient as one flat vector
*
* @return
*/
INDArray gradient();
/**
* Clear residual parameters (useful for returning a gradient and then clearing old objects)
*/
void clear();
/**
* The gradient for the given variable
*
* @param variable the variable to get the gradient for
* @return the gradient for the given variable or null
*/
INDArray getGradientFor(String variable);
/**
* Update gradient for the given variable
*
* @param variable the variable to get the gradient for
* @param gradient the gradient values
* @return the gradient for the given variable or null
*/
INDArray setGradientFor(String variable, INDArray gradient);
/**
* Update gradient for the given variable; also (optionally) specify the order in which the array should be flattened
* to a row vector
*
* @param variable the variable to get the gradient for
* @param gradient the gradient values
* @param flatteningOrder the order in which gradients should be flattened (null ok - default)
* @return the gradient for the given variable or null
*/
INDArray setGradientFor(String variable, INDArray gradient, Character flatteningOrder);
/**
* Return the gradient flattening order for the specified variable, or null if it is not explicitly set
* @param variable Variable to return the gradient flattening order for
* @return Order in which the specified variable's gradient should be flattened
*/
Character flatteningOrderForVariable(String variable);
}