org.nd4j.linalg.api.ops.IndexAccumulation 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.api.ops;
import org.nd4j.linalg.primitives.Pair;
/**An index accumulation is an operation that returns an index within
* a NDArray.
* Examples of IndexAccumulation operations include finding the index
* of the minimim value, index of the maximum value, index of the first
* element equal to value y, index of the maximum pair-wise difference
* between two NDArrays X and Y etc.
*
* Index accumulation is similar to {@link Accumulation} in that both are
* accumulation/reduction operations, however index accumulation returns
* an integer corresponding to an index, rather than a real (or complex)
* value.
*
* Index accumulation operations generally have 3 inputs:
* x -> the origin ndarray
* y -> the pairwise ndarray (frequently null/not applicable)
* n -> the number of times to accumulate
*
* Note that IndexAccumulation op implementations should be stateless
* (other than the final result and x/y/n arguments) and hence threadsafe,
* such that they may be parallelized using the update, combineSubResults
* and set/getFinalResults methods.
*/
public interface IndexAccumulation extends Op {
/** Set the final index/result of the accumulation. */
void setFinalResult(int idx);
/** Get the final result of the IndexAccumulation */
int getFinalResult();
/**Initial value for the index accumulation
*@return the initial value
*/
double zeroDouble();
/** Initial value for the index accumulation.
* @return the initial value
* */
float zeroFloat();
/** Initial value for the index accumulation.
* @return the initial value
* */
float zeroHalf();
/** The initial value and initial index to use
* for the accumulation
* @return
*/
Pair zeroPair();
}