org.nd4j.linalg.api.ops.impl.transforms.SELU Maven / Gradle / Ivy
/*-
*
* * Copyright 2015 Skymind,Inc.
* *
* * Licensed under the Apache License, Version 2.0 (the "License");
* * you may not use this file except in compliance with the License.
* * You may obtain a copy of the License at
* *
* * http://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
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package org.nd4j.linalg.api.ops.impl.transforms;
import org.apache.commons.math3.util.FastMath;
import org.nd4j.linalg.api.complex.IComplexNumber;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.api.ops.BaseTransformOp;
import org.nd4j.linalg.api.ops.Op;
import org.nd4j.linalg.api.ops.TransformOp;
/**
* SELU activation function
*
* https://arxiv.org/pdf/1706.02515.pdf
*
* @author [email protected]
*/
public class SELU extends BaseTransformOp {
private static final double SELU_ALPHA = 1.6732632423543772848170429916717;
private static final double SELU_LAMBDA = 1.0507009873554804934193349852946;
public SELU() {}
public SELU(INDArray x, INDArray z) {
super(x, z);
}
public SELU(INDArray x, INDArray z, long n) {
super(x, z, n);
}
public SELU(INDArray x) {
super(x);
}
@Override
public int opNum() {
return 67;
}
@Override
public String name() {
return "selu";
}
@Override
public IComplexNumber op(IComplexNumber origin, double other) {
throw new UnsupportedOperationException();
}
@Override
public IComplexNumber op(IComplexNumber origin, float other) {
throw new UnsupportedOperationException();
}
@Override
public IComplexNumber op(IComplexNumber origin, IComplexNumber other) {
throw new UnsupportedOperationException();
}
@Override
public float op(float origin, float other) {
throw new UnsupportedOperationException();
}
@Override
public double op(double origin, double other) {
throw new UnsupportedOperationException();
}
@Override
public double op(double d1) {
return d1 > 0.0f ? SELU_LAMBDA * d1 : SELU_LAMBDA * (SELU_ALPHA * FastMath.exp(d1) - SELU_ALPHA);
}
@Override
public float op(float d1) {
return d1 > 0.0f ? (float) SELU_LAMBDA * d1 : (float) ((float) SELU_LAMBDA * ((float) SELU_ALPHA * FastMath.exp(d1) - (float) SELU_ALPHA));
}
@Override
public IComplexNumber op(IComplexNumber origin) {
throw new UnsupportedOperationException();
}
@Override
public TransformOp derivative() {
return new SELUDerivative(x, z, n);
}
@Override
public Op opForDimension(int index, int dimension) {
INDArray xAlongDimension = x.vectorAlongDimension(index, dimension);
return new SELU(xAlongDimension, z.vectorAlongDimension(index, dimension), xAlongDimension.length());
}
@Override
public Op opForDimension(int index, int... dimension) {
INDArray xAlongDimension = x.tensorAlongDimension(index, dimension);
return new SELU(xAlongDimension, z.tensorAlongDimension(index, dimension), xAlongDimension.length());
}
}