org.nd4j.linalg.api.ops.impl.shape.SizeAt 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.impl.shape;
import org.nd4j.autodiff.samediff.SDVariable;
import org.nd4j.autodiff.samediff.SameDiff;
import org.nd4j.base.Preconditions;
import org.nd4j.imports.NoOpNameFoundException;
import org.nd4j.linalg.api.buffer.DataType;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.api.ops.DynamicCustomOp;
import org.nd4j.linalg.api.ops.Op;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* Returns the size of the input along given dimension as a rank 0 array
*
* @author [email protected]
*/
public class SizeAt extends DynamicCustomOp {
public SizeAt() {}
public SizeAt(INDArray input, int dimension) {
this(input, null, dimension);
}
public SizeAt(INDArray input, INDArray output, int dimension) {
super(null,input, output, new ArrayList(), new int[]{dimension});
}
public SizeAt(SameDiff sameDiff, SDVariable input, int dimension) {
super(null, sameDiff, new SDVariable[] {input}, false);
iArguments.add(Long.valueOf(dimension));
}
@Override
public String opName() {
return "size_at";
}
@Override
public Op.Type opType() {
return Op.Type.CUSTOM;
}
@Override
public List doDiff(List i_v) {
return Collections.singletonList(sameDiff.zerosLike(arg()));
}
@Override
public List calculateOutputDataTypes(List dataTypes){
Preconditions.checkState(dataTypes.size() == 1, "Expected list with exactly 1 datatype for %s, got %s", getClass(), dataTypes);
//Output type is always long (i.e., size of array)
return Collections.singletonList(DataType.LONG);
}
}