You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
68 lines
1.3 KiB
68 lines
1.3 KiB
/* _Sinh function */
|
|
#include "wctype.h"
|
|
#include "xmath.h"
|
|
_STD_BEGIN
|
|
|
|
/* coefficients */
|
|
#define NP (sizeof (p) / sizeof (p[0]) - 1)
|
|
static const double p[] = { /* courtesy Dr. Tim Prince */
|
|
0.0000000001632881,
|
|
0.0000000250483893,
|
|
0.0000027557344615,
|
|
0.0001984126975233,
|
|
0.0083333333334816,
|
|
0.1666666666666574,
|
|
1.0000000000000001};
|
|
|
|
_CRTIMP2 double __cdecl _Sinh(double x, double y)
|
|
{ /* compute y*sinh(x), |y| <= 1 */
|
|
switch (_Dtest(&x))
|
|
{ /* test for special codes */
|
|
case NAN:
|
|
errno = EDOM;
|
|
return (x);
|
|
case INF:
|
|
if (y == 0)
|
|
return (0);
|
|
errno = ERANGE;
|
|
return (DSIGN(x) ? -_Inf._D : _Inf._D);
|
|
case 0:
|
|
return (0);
|
|
default: /* finite */
|
|
{ /* compute sinh(finite) */
|
|
short neg;
|
|
|
|
if (x < 0)
|
|
x = -x, neg = 1;
|
|
else
|
|
neg = 0;
|
|
if (x < _Rteps._D)
|
|
x *= y; /* x tiny */
|
|
else if (x < 1)
|
|
{
|
|
double w = x * x;
|
|
|
|
x += x * w * _Poly(w, p, NP - 1);
|
|
x *= y;
|
|
}
|
|
else if (x < _Xbig)
|
|
{ /* worth adding in exp(-x) */
|
|
_Exp(&x, 1, -1);
|
|
x = y * (x - 0.25 / x);
|
|
}
|
|
else if (0 <= _Exp(&x, y, -1))
|
|
errno = ERANGE; /* x large */
|
|
return (neg ? -x : x);
|
|
}
|
|
}
|
|
}
|
|
_STD_END
|
|
|
|
/*
|
|
* Copyright (c) 1994 by P.J. Plauger. ALL RIGHTS RESERVED.
|
|
* Consult your license regarding permissions and restrictions.
|
|
*/
|
|
|
|
/*
|
|
941029 pjp: added _STD machinery
|
|
*/
|