/*
* Artificial Intelligence for Humans
* Volume 2: Nature Inspired Algorithms
* Java Version
* http://www.aifh.org
* http://www.jeffheaton.com
*
* Code repository:
* https://github.com/jeffheaton/aifh
*
* Copyright 2014 by Jeff Heaton
*
* 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
* limitations under the License.
*
* For more information on Heaton Research copyrights, licenses
* and trademarks visit:
* http://www.heatonresearch.com/copyright
*/
package com.heatonresearch.aifh.general.fns.link;
import com.heatonresearch.aifh.AIFHError;
import com.heatonresearch.aifh.general.fns.Fn;
/**
* The log link function for a GLM.
* <p/>
* http://en.wikipedia.org/wiki/Generalized_linear_model
*/
public class LogLinkFunction implements Fn {
/**
* {@inheritDoc}
*/
@Override
public double evaluate(final double[] x) {
if (x.length > 1) {
throw new AIFHError("The logistic link function can only accept one parameter.");
}
return Math.log(x[0]);
}
}