sigmodperceptron.java.svn-base

AI大作业实现神经网络的小程序

package perceptron;

import java.io.*;

public class SigmodPerceptron extends Perceptron {

	public SigmodPerceptron(int layer, int id, int nin, double lrate,
			double threshold) {
		super(layer, id, nin, lrate, threshold);
	}

	public SigmodPerceptron(InputStream is) {
		super(is);
	}

	/**
	 * Simple function.
	 * 
	 * Overiable.
	 * 
	 * @param s=weight
	 *            dotProduct input.
	 * @return
	 */
	double f(double s) {
		return 1.0 / (1.0 + Math.exp(-s));
	}

	/**
	 * f'
	 * 
	 * Overiable.
	 * 
	 * @param s
	 * @return
	 */

	double differential(double s) {
		return f(s) * (1 - f(s));
	}

}