CocoRoboDesktop/pdf1.js/node_modules/cephes/cephes/sinh.c

/*							sinh.c
 *
 *	Hyperbolic sine
 *
 *
 *
 * SYNOPSIS:
 *
 * double x, y, sinh();
 *
 * y = sinh( x );
 *
 *
 *
 * DESCRIPTION:
 *
 * Returns hyperbolic sine of argument in the range MINLOG to
 * MAXLOG.
 *
 * The range is partitioned into two segments.  If |x| <= 1, a
 * rational function of the form x + x**3 P(x)/Q(x) is employed.
 * Otherwise the calculation is sinh(x) = ( exp(x) - exp(-x) )/2.
 *
 *
 *
 * ACCURACY:
 *
 *                      Relative error:
 * arithmetic   domain     # trials      peak         rms
 *    DEC      +- 88        50000       4.0e-17     7.7e-18
 *    IEEE     +-MAXLOG     30000       2.6e-16     5.7e-17
 *
 */

/*
Cephes Math Library Release 2.8:  June, 2000
Copyright 1984, 1995, 2000 by Stephen L. Moshier
*/

#include "mconf.h"

#ifdef UNK
static double P[] = {-7.89474443963537015605E-1, -1.63725857525983828727E2,
                     -1.15614435765005216044E4, -3.51754964808151394800E5};
static double Q[] = {
    /* 1.00000000000000000000E0,*/
    -2.77711081420602794433E2, 3.61578279834431989373E4,
    -2.11052978884890840399E6};
#endif

#ifdef DEC
static unsigned short P[] = {
    0140112, 0015377, 0042731, 0163255, 0142043, 0134721, 0146177, 0123761,
    0143464, 0122706, 0034353, 0006017, 0144653, 0140536, 0157665, 0054045};
static unsigned short Q[] = {
    /*0040200,0000000,0000000,0000000,*/
    0142212, 0155404, 0133513, 0022040, 0044015, 0036723,
    0173271, 0011053, 0145400, 0150407, 0023710, 0001034};
#endif

#ifdef IBMPC
static unsigned short P[] = {0x3cd6, 0xe8bb, 0x435f, 0xbfe9, 0xf4fe, 0x398f,
                             0x773a, 0xc064, 0x6182, 0xc71d, 0x94b8, 0xc0c6,
                             0xab05, 0xdbf6, 0x782b, 0xc115};
static unsigned short Q[] = {
    /*0x0000,0x0000,0x0000,0x3ff0,*/
    0x6484, 0x96e9, 0x5b60, 0xc071, 0x2245, 0x7ed7,
    0xa7ba, 0x40e1, 0x0044, 0xe4f9, 0x1a20, 0xc140};
#endif

#ifdef MIEEE
static unsigned short P[] = {0xbfe9, 0x435f, 0xe8bb, 0x3cd6, 0xc064, 0x773a,
                             0x398f, 0xf4fe, 0xc0c6, 0x94b8, 0xc71d, 0x6182,
                             0xc115, 0x782b, 0xdbf6, 0xab05};
static unsigned short Q[] = {0xc071, 0x5b60, 0x96e9, 0x6484, 0x40e1, 0xa7ba,
                             0x7ed7, 0x2245, 0xc140, 0x1a20, 0xe4f9, 0x0044};
#endif

#ifdef ANSIPROT
extern double fabs(double);
extern double exp(double);
extern double polevl(double, void *, int);
extern double p1evl(double, void *, int);
#else
double fabs(), exp(), polevl(), p1evl();
#endif
extern double INFINITY, MINLOG, MAXLOG, LOGE2;

double sinh(x) double x;
{
  double a;

#ifdef MINUSZERO
  if (x == 0.0)
    return (x);
#endif
  a = fabs(x);
  if ((x > (MAXLOG + LOGE2)) || (x > -(MINLOG - LOGE2))) {
    mtherr("sinh", DOMAIN);
    if (x > 0)
      return (INFINITY);
    else
      return (-INFINITY);
  }
  if (a > 1.0) {
    if (a >= (MAXLOG - LOGE2)) {
      a = exp(0.5 * a);
      a = (0.5 * a) * a;
      if (x < 0)
        a = -a;
      return (a);
    }
    a = exp(a);
    a = 0.5 * a - (0.5 / a);
    if (x < 0)
      a = -a;
    return (a);
  }

  a *= a;
  return (x + x * a * (polevl(a, P, 3) / p1evl(a, Q, 3)));
}