org.nd4j.linalg.api.ops.impl.transforms.DynamicStitch Maven / Gradle / Ivy
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* 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.
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* 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
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* SPDX-License-Identifier: Apache-2.0
******************************************************************************/
package org.nd4j.linalg.api.ops.impl.transforms;
import org.apache.commons.lang3.ArrayUtils;
import org.nd4j.autodiff.samediff.SDVariable;
import org.nd4j.autodiff.samediff.SameDiff;
import org.nd4j.imports.NoOpNameFoundException;
import org.nd4j.imports.graphmapper.tf.TFGraphMapper;
import org.nd4j.linalg.api.ops.DynamicCustomOp;
import org.tensorflow.framework.AttrValue;
import org.tensorflow.framework.GraphDef;
import org.tensorflow.framework.NodeDef;
import java.util.*;
/**
* Transforms a given input tensor into numPartitions partitions, as indicated by the indices in "partitions".
* Output tensor has one more dimension than input tensor, the first dimension indicates the partition.
*
* Example:
*
* input: [4, 3, 5, 7, 8, 0]
* input shape: [1, 6]
* partitions: [1, 0, 1, 0, 0, 1]
* numPartitions: 2
* outputs[0]: [3, 7, 8]
* outputs[1]: [4, 5, 0]
*
* @author Max Pumperla
*/
public class DynamicStitch extends DynamicCustomOp {
private int numPartitions;
private SDVariable[] indices;
public DynamicStitch() {
}
public DynamicStitch(SameDiff sameDiff, SDVariable[] indices, SDVariable[] inputs) {
super(null, sameDiff, ArrayUtils.addAll(indices, inputs), false);
this.indices = indices;
this.numPartitions = inputs.length;
}
@Override
public List doDiff(List i_v) {
// DynamicPartition and DynamicStitch are mutually inverse
SDVariable gradient = i_v.get(0);
SDVariable[] partitionData = new SDVariable[indices.length];
for (int i = 0; i < indices.length; i++)
partitionData[i] = sameDiff.onesLike(indices[i]).mul(i);
SDVariable partitions = sameDiff.dynamicStitch(indices, partitionData);
SDVariable[] partition = sameDiff.dynamicPartition(gradient, partitions, numPartitions);
List ret = new ArrayList<>();
for (SDVariable i : indices)
ret.add(f().zerosLike(i));
Collections.addAll(ret, partition);
return ret;
}
@Override
public void initFromTensorFlow(NodeDef nodeDef, SameDiff initWith, Map attributesForNode, GraphDef graph) {
TFGraphMapper.getInstance().initFunctionFromProperties(nodeDef.getOp(), this, attributesForNode, nodeDef, graph);
}
@Override
public String opName() {
return "dynamic_stitch";
}
@Override
public String[] tensorflowNames() {
return new String[]{"DynamicStitch", "ParallelDynamicStitch"};
}
@Override
public String onnxName() {
throw new NoOpNameFoundException("No onnx name found for shape " + opName());
}
}