mirror of
https://github.com/reactos/reactos.git
synced 2024-08-22 03:12:51 +00:00
25 lines
372 B
C
25 lines
372 B
C
/* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */
|
|
|
|
#include <math.h>
|
|
|
|
#ifdef _MSC_VER
|
|
#pragma function(tanh)
|
|
#endif
|
|
|
|
/*
|
|
* @implemented
|
|
*/
|
|
double tanh(double x)
|
|
{
|
|
if (x > 50)
|
|
return 1;
|
|
else if (x < -50)
|
|
return -1;
|
|
else
|
|
{
|
|
const double ebig = exp(x);
|
|
const double esmall = 1.0/ebig;
|
|
return (ebig - esmall) / (ebig + esmall);
|
|
}
|
|
}
|