ciir.umass.edu.learning.neuralnet.LogiFunction Maven / Gradle / Ivy
/*===============================================================================
* Copyright (c) 2010-2012 University of Massachusetts. All Rights Reserved.
*
* Use of the RankLib package is subject to the terms of the software license set
* forth in the LICENSE file included with this software, and also available at
* http://people.cs.umass.edu/~vdang/ranklib_license.html
*===============================================================================
*/
package ciir.umass.edu.learning.neuralnet;
/**
* @author vdang
*/
public class LogiFunction implements TransferFunction {
@Override
public double compute(double x)
{
return (double) (1.0 / (1.0 + Math.exp(-x)));
}
@Override
public double computeDerivative(double x)
{
double output = compute(x);
return (double) (output * (1.0 - output));
}
}