/*----------------------------------------------------------------------*/
/*  functions.c:  Sigmoidal functions        				*/
/*----------------------------------------------------------------------*/

#include <math.h>
#include "function_exp.h"

float Tanh(number)
{
   return tanh(number);
}

float DTanh(number)
float number;
{
   return (1. - number * number);
}

float Expon(number)
float number;
{
   return (1. / (1. + exp(-number)));
}

float DExpon(number)
float number;
{
   return (number * (1. - number));
}

float Sin(number)
float number;
{
   float n2;

   if (number < -1.570796) n2 =  -1.;
   else if (number > 1.570796) n2 = 1.; 
   else n2 = sin(number);
   return n2;
}

float DSin(number)
float number;
{
   return sqrt(1. - (number)*(number));
} 

float Signum(number)
float number;
{
   return ((number) > 0 ? 1. : -1.);
}

float Binary(number)
float number;
{
   return (fabs(number) > .5 ? 1. : 0.);
}