blob: 81e428aaa3f112a3c8d9507c804ba96141e8c8b7 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
|
#include <u.h>
#include <base.h>
/*
tanh(arg) computes the hyperbolic tangent of its floating
point argument.
sinh and cosh are called except for large arguments, which
would cause overflow improperly.
*/
double
math·tanh(double arg)
{
if(arg < 0) {
arg = -arg;
if(arg > 21)
return -1;
return -math·sinh(arg)/math·cosh(arg);
}
if(arg > 21)
return 1;
return math·sinh(arg)/math·cosh(arg);
}
|
