org.nd4j.linalg.api.ops.impl.reduce3.CosineSimilarity Maven / Gradle / Ivy
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package org.nd4j.linalg.api.ops.impl.reduce3;
import org.nd4j.autodiff.samediff.SDVariable;
import org.nd4j.autodiff.samediff.SameDiff;
import org.nd4j.autodiff.util.SameDiffUtils;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.factory.Nd4j;
import java.util.Arrays;
import java.util.List;
public class CosineSimilarity extends BaseReduce3Op {
public static final String OP_NAME = "cosinesimilarity";
public CosineSimilarity(SameDiff sameDiff, SDVariable i_v, int[] dimensions) {
super(sameDiff, i_v, dimensions);
}
public CosineSimilarity(SameDiff sameDiff, SDVariable i_v, SDVariable i_v2, int[] dimensions) {
super(sameDiff, i_v, i_v2, dimensions);
}
public CosineSimilarity(SameDiff sameDiff, SDVariable i_v, SDVariable dimensions) {
super(sameDiff, i_v, dimensions);
}
public CosineSimilarity(SameDiff sameDiff, SDVariable i_v, SDVariable i_v2, SDVariable dimensions) {
super(sameDiff, i_v, i_v2, dimensions);
}
public CosineSimilarity() {
extraArgs = new Object[]{0.0f, 0.0f};
}
public CosineSimilarity(INDArray x, INDArray y, INDArray z, int... dimensions) {
super(x, y, z, dimensions);
extraArgs = new Object[]{0.0f, 0.0f};
}
public CosineSimilarity(INDArray x, INDArray y, int... dimensions) {
this(x, y, null, dimensions);
}
public CosineSimilarity(INDArray x, INDArray y, INDArray z) {
this(x, y, z, null);
}
public CosineSimilarity(INDArray x, INDArray y, INDArray z, boolean allDistances, int... dimension) {
this(x, y, z, dimension);
this.isComplex = allDistances;
}
public CosineSimilarity(INDArray x, INDArray y, boolean allDistances, int... dimension) {
this(x, y, null, allDistances, dimension);
}
public CosineSimilarity(INDArray x, INDArray y, INDArray z, boolean keepDims, boolean allDistances, int... dimensions){
super(x, y, z, keepDims, allDistances, dimensions);
extraArgs = new Object[]{0.0f, 0.0f};
}
public CosineSimilarity(SameDiff sd, SDVariable x, SDVariable y, boolean keepDims, boolean isComplex, int[] dimensions) {
super(sd, x, y, keepDims, isComplex, dimensions);
}
public CosineSimilarity(INDArray x, INDArray y, boolean keepDims, boolean isComplex, int[] dimensions) {
super(x,y,null,keepDims,isComplex,dimensions);
}
@Override
public int opNum() {
return 2;
}
@Override
public String opName() {
return OP_NAME;
}
@Override
public List doDiff(List i_v1) {
//Let cosine(x,y) = a / b
//a = sum_i (x_i * y_i)
//b = sqrt(sum_i x_i^2) * sqrt(sum_i y_i^2) = l2(x) * l2(y)
//Then:
// dc(x,y)/dx_i = 1/b * (y - x * a / (l2(x))^2)
return doDiff(sameDiff, larg(), rarg(), i_v1.get(0), keepDims, dimensions);
}
public static List doDiff(SameDiff sameDiff, SDVariable x, SDVariable y,
SDVariable gradOut, boolean keepDims, int... dimensions){
SDVariable a = sameDiff.sum(x.mul(y),true, dimensions);
SDVariable l2x = sameDiff.norm2(x, true, dimensions);
SDVariable l2y = sameDiff.norm2(y, true, dimensions);
SDVariable b = l2x.mul(l2y);
SDVariable l2xSq = sameDiff.math().square(l2x);
SDVariable l2ySq = sameDiff.math().square(l2y);
SDVariable broadcastableGrad;
if(keepDims || dimensions == null || dimensions.length == 0 || (dimensions.length == 1 && dimensions[0] == Integer.MAX_VALUE)){
//keepDims or full array reduction
broadcastableGrad = gradOut;
} else {
broadcastableGrad = SameDiffUtils.reductionBroadcastableWithOrigShape(x, sameDiff.constant(Nd4j.createFromArray(dimensions)), gradOut);
}
SDVariable dcdx = y.sub(x.mul(a).div(l2xSq)).div(b);
SDVariable dcdy = x.sub(y.mul(a).div(l2ySq)).div(b);
return Arrays.asList(dcdx.mul(broadcastableGrad), dcdy.mul(broadcastableGrad));
}
}