org.nd4j.linalg.ops.transforms.Log Maven / Gradle / Ivy
package org.nd4j.linalg.ops.transforms;
import org.nd4j.linalg.api.complex.IComplexNumber;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.factory.Nd4j;
import org.nd4j.linalg.ops.BaseElementWiseOp;
import org.nd4j.linalg.util.ComplexUtil;
/**
* Log transform
*
* @author Adam Gibson
*/
public class Log extends BaseElementWiseOp {
/**
* The transformation for a given value (a scalar ndarray)
*
* @param value the value to applyTransformToOrigin (a scalar ndarray)
* @param i the index of the element being acted upon
* @return the transformed value based on the input
*/
@Override
public Object apply(INDArray from,Object value, int i) {
if(value instanceof IComplexNumber) {
return ComplexUtil.abs((org.nd4j.linalg.api.complex.IComplexNumber) value);
}
double ret = Math.log( (double) value);
if(Double.isNaN(ret) || Double.isInfinite(ret))
return Nd4j.EPS_THRESHOLD;
return ret;
}
}