org.nd4j.linalg.api.ops.ReduceOp 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.
*
* Unless required by applicable law or agreed to in writing, software
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* SPDX-License-Identifier: Apache-2.0
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package org.nd4j.linalg.api.ops;
import org.nd4j.linalg.api.buffer.DataType;
import org.nd4j.linalg.api.ndarray.INDArray;
/**
* An accumulation is an op that given:
* x -> the origin ndarray
* y -> the pairwise ndarray
* n -> the number of times to accumulate
*
*
* Of note here in the extra arguments.
*
* An accumulation (or reduction in some terminology)
* has a concept of a starting value.
*
* The starting value is the initialization of the solution
* to the operation.
*
* An accumulation should always have the extraArgs()
* contain the zero value as the first value.
*
* This allows the architecture to generalize to different backends
* and gives the implementer of a backend a way of hooking in to
* passing parameters to different engines.
*
* Note that ReduceOp op implementations should be stateless
* (other than the final result and x/y/z/n arguments) and hence threadsafe,
* such that they may be parallelized using the update, combineSubResults and
* set/getFinalResults methods.
* @author Adam Gibson
*/
public interface ReduceOp extends Op {
/**
* Returns the no op version
* of the input
* Basically when a reduce can't happen (eg: sum(0) on a row vector)
* you have a no op state for a given reduction.
* For most accumulations, this should return x
* but certain transformations should return say: the absolute value
*
*
* @return the no op version of the input
*/
INDArray noOp();
/**
* This method returns dimensions for this op
* @return
*/
INDArray dimensions();
@Deprecated
boolean isComplexAccumulation();
Type getOpType();
/**
* This method returns TRUE if we're going to keep axis, FALSE otherwise
*
* @return
*/
boolean isKeepDims();
/**
* This method returns datatype for result array wrt given inputs
* @return
*/
DataType resultType();
boolean validateDataTypes();
Number getFinalResult();
void setDimensions(int... dimensions);
}