org.nd4j.linalg.api.ops.impl.transforms.custom.DotProductAttentionBp Maven / Gradle / Ivy
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* Copyright (c) 2015-2019 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.transforms.custom;
import lombok.NoArgsConstructor;
import org.nd4j.autodiff.samediff.SDVariable;
import org.nd4j.autodiff.samediff.SameDiff;
import org.nd4j.base.Preconditions;
import org.nd4j.linalg.api.buffer.DataType;
import org.nd4j.linalg.api.ops.DynamicCustomOp;
import java.util.Arrays;
import java.util.List;
/**
* (optionally scaled) dot product attention Backprop
*
* See also "Attention is all you need" (https://arxiv.org/abs/1706.03762, p. 4, eq. 1)
*
* @author Paul Dubs
*/
@NoArgsConstructor
public class DotProductAttentionBp extends DynamicCustomOp {
private boolean scaled;
public DotProductAttentionBp(SameDiff sameDiff, SDVariable queries, SDVariable keys, SDVariable values, SDVariable eps, SDVariable mask, boolean scaled) {
super(null, sameDiff, mask == null ? new SDVariable[] {queries, keys, values, eps} : new SDVariable[] {queries, keys, values, eps, mask}, false);
this.scaled = scaled;
addIArgument(scaled ? 1 : 0);
}
@Override
public String opName() {
return "dot_product_attention_bp";
}
@Override
public List doDiff(List grad){
throw new UnsupportedOperationException("Differentiation of " + getClass().getName() + " not supported");
}
@Override
public List calculateOutputDataTypes(List dataTypes){
Preconditions.checkState(dataTypes != null && (dataTypes.size() == 4 || dataTypes.size() == 5), "Expected 4 or 5 input datatypes, got %s", dataTypes);
DataType first = dataTypes.get(0);
for( int i=0; i 0){
Preconditions.checkState(first == dataTypes.get(i), "All datatypes must be same type, got input datatypes %s", dataTypes);
}
}
return Arrays.asList(first, first, first);
}
}