threshold.c

一个不错的GA-NN的神经网络模型的示范代码。适合入门学习

/*  threshold.c */

/* 	Copyright 2004 Oswaldo Morizaki */

/* 	This file is part of ga-nn-ag.

    ga-nn-ag is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    ga-nn-ag is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with ga-nn-ag; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include "my_header.h"
#include "aux_prot.h"

double threshold(int threshold_type, float net, float threshold_level)
{
	double temp;
	double temp1;

	switch(threshold_type)
	{
		case 0: temp=net; break;
		case 1: {
					exp(-net);  //required for bug gcc 3.3.2 Fedora Core 1
					temp1=1+exp(-net);
					temp=threshold_level/temp1;
					break;
					}
	}
	
//	syslog(LOG_INFO,"temp1 = %f, temp = %f", temp1, temp);
	
	return( temp > threshold_level-0.1 ? threshold_level-0.1 : 
				temp < 0.1 ? 0.1 : temp);
}