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

/*							dawsn.c
 *
 *	Dawson's Integral
 *
 *
 *
 * SYNOPSIS:
 *
 * double x, y, dawsn();
 *
 * y = dawsn( x );
 *
 *
 *
 * DESCRIPTION:
 *
 * Approximates the integral
 *
 *                             x
 *                             -
 *                      2     | |        2
 *  dawsn(x)  =  exp( -x  )   |    exp( t  ) dt
 *                          | |
 *                           -
 *                           0
 *
 * Three different rational approximations are employed, for
 * the intervals 0 to 3.25; 3.25 to 6.25; and 6.25 up.
 *
 *
 * ACCURACY:
 *
 *                      Relative error:
 * arithmetic   domain     # trials      peak         rms
 *    IEEE      0,10        10000       6.9e-16     1.0e-16
 *    DEC       0,10         6000       7.4e-17     1.4e-17
 *
 *
 */

/*							dawsn.c */

/*
Cephes Math Library Release 2.8:  June, 2000
Copyright 1984, 1987, 1989, 2000 by Stephen L. Moshier
*/

#include "mconf.h"
/* Dawson's integral, interval 0 to 3.25 */
#ifdef UNK
static double AN[10] = {
    1.13681498971755972054E-11, 8.49262267667473811108E-10,
    1.94434204175553054283E-8,  9.53151741254484363489E-7,
    3.07828309874913200438E-6,  3.52513368520288738649E-4,
    -8.50149846724410912031E-4, 4.22618223005546594270E-2,
    -9.17480371773452345351E-2, 9.99999999999999994612E-1,
};
static double AD[11] = {
    2.40372073066762605484E-11, 1.48864681368493396752E-9,
    5.21265281010541664570E-8,  1.27258478273186970203E-6,
    2.32490249820789513991E-5,  3.25524741826057911661E-4,
    3.48805814657162590916E-3,  2.79448531198828973716E-2,
    1.58874241960120565368E-1,  5.74918629489320327824E-1,
    1.00000000000000000539E0,
};
#endif
#ifdef DEC
static unsigned short AN[40] = {
    0027107, 0176630, 0075752, 0107612, 0030551, 0070604, 0166707, 0127727,
    0031647, 0002210, 0117120, 0056376, 0033177, 0156026, 0141275, 0140627,
    0033516, 0112200, 0037035, 0165515, 0035270, 0150613, 0016423, 0105634,
    0135536, 0156227, 0023515, 0044413, 0037055, 0015273, 0105147, 0064025,
    0137273, 0163145, 0014460, 0166465, 0040200, 0000000, 0000000, 0000000,
};
static unsigned short AD[44] = {
    0027323, 0067372, 0115566, 0131320, 0030714, 0114432, 0074206, 0006637,
    0032137, 0160671, 0044203, 0026344, 0033252, 0146656, 0020247, 0100231,
    0034303, 0003346, 0123260, 0022433, 0035252, 0125460, 0173041, 0155415,
    0036144, 0113747, 0125203, 0124617, 0036744, 0166232, 0143671, 0133670,
    0037442, 0127755, 0162625, 0000100, 0040023, 0026736, 0003604, 0106265,
    0040200, 0000000, 0000000, 0000000,
};
#endif
#ifdef IBMPC
static unsigned short AN[40] = {
    0x51f1, 0x0f7d, 0xffb3, 0x3da8, 0xf5fb, 0x9db8, 0x2e30, 0x3e0d,
    0x0ba0, 0x13ca, 0xe091, 0x3e54, 0xb833, 0xd857, 0xfb82, 0x3eaf,
    0xbd6a, 0x07c3, 0xd290, 0x3ec9, 0x7174, 0x63a2, 0x1a31, 0x3f37,
    0xa921, 0xe4e9, 0xdb92, 0xbf4b, 0xed03, 0x714c, 0xa357, 0x3fa5,
    0x1da7, 0xa326, 0x7ccc, 0xbfb7, 0x0000, 0x0000, 0x0000, 0x3ff0,
};
static unsigned short AD[44] = {
    0xd65a, 0x536e, 0x6ddf, 0x3dba, 0xc1b4, 0x4f10, 0x9323, 0x3e19, 0x659c,
    0x2910, 0xfc37, 0x3e6b, 0xf013, 0xc414, 0x59b5, 0x3eb5, 0x04a3, 0xd4d6,
    0x60dc, 0x3ef8, 0x3b62, 0x1ec4, 0x5566, 0x3f35, 0x7532, 0xf550, 0x92fc,
    0x3f6c, 0x36f7, 0x58f7, 0x9d93, 0x3f9c, 0xa008, 0xbcb2, 0x55fd, 0x3fc4,
    0x9197, 0xc0f0, 0x65bb, 0x3fe2, 0x0000, 0x0000, 0x0000, 0x3ff0,
};
#endif
#ifdef MIEEE
static unsigned short AN[40] = {
    0x3da8, 0xffb3, 0x0f7d, 0x51f1, 0x3e0d, 0x2e30, 0x9db8, 0xf5fb,
    0x3e54, 0xe091, 0x13ca, 0x0ba0, 0x3eaf, 0xfb82, 0xd857, 0xb833,
    0x3ec9, 0xd290, 0x07c3, 0xbd6a, 0x3f37, 0x1a31, 0x63a2, 0x7174,
    0xbf4b, 0xdb92, 0xe4e9, 0xa921, 0x3fa5, 0xa357, 0x714c, 0xed03,
    0xbfb7, 0x7ccc, 0xa326, 0x1da7, 0x3ff0, 0x0000, 0x0000, 0x0000,
};
static unsigned short AD[44] = {
    0x3dba, 0x6ddf, 0x536e, 0xd65a, 0x3e19, 0x9323, 0x4f10, 0xc1b4, 0x3e6b,
    0xfc37, 0x2910, 0x659c, 0x3eb5, 0x59b5, 0xc414, 0xf013, 0x3ef8, 0x60dc,
    0xd4d6, 0x04a3, 0x3f35, 0x5566, 0x1ec4, 0x3b62, 0x3f6c, 0x92fc, 0xf550,
    0x7532, 0x3f9c, 0x9d93, 0x58f7, 0x36f7, 0x3fc4, 0x55fd, 0xbcb2, 0xa008,
    0x3fe2, 0x65bb, 0xc0f0, 0x9197, 0x3ff0, 0x0000, 0x0000, 0x0000,
};
#endif

/* interval 3.25 to 6.25 */
#ifdef UNK
static double BN[11] = {
    5.08955156417900903354E-1,  -2.44754418142697847934E-1,
    9.41512335303534411857E-2,  -2.18711255142039025206E-2,
    3.66207612329569181322E-3,  -4.23209114460388756528E-4,
    3.59641304793896631888E-5,  -2.14640351719968974225E-6,
    9.10010780076391431042E-8,  -2.40274520828250956942E-9,
    3.59233385440928410398E-11,
};
static double BD[10] = {
    /*  1.00000000000000000000E0,*/
    -6.31839869873368190192E-1, 2.36706788228248691528E-1,
    -5.31806367003223277662E-2, 8.48041718586295374409E-3,
    -9.47996768486665330168E-4, 7.81025592944552338085E-5,
    -4.55875153252442634831E-6, 1.89100358111421846170E-7,
    -4.91324691331920606875E-9, 7.18466403235734541950E-11,
};
#endif
#ifdef DEC
static unsigned short BN[44] = {
    0040002, 0045342, 0113762, 0004360, 0137572, 0120346, 0172745, 0144046,
    0037300, 0151134, 0123440, 0117047, 0136663, 0025423, 0014755, 0046026,
    0036157, 0177561, 0027535, 0046744, 0135335, 0161052, 0071243, 0146535,
    0034426, 0154060, 0164506, 0135625, 0133420, 0005356, 0100017, 0151334,
    0032303, 0066137, 0024013, 0046212, 0131045, 0016612, 0066270, 0047574,
    0027435, 0177025, 0060625, 0116363,
};
static unsigned short BD[40] = {
    /*0040200,0000000,0000000,0000000,*/
    0140041, 0140101, 0174552, 0037073, 0037562, 0061503, 0124271, 0160756,
    0137131, 0151760, 0073210, 0110534, 0036412, 0170562, 0117017, 0155377,
    0135570, 0101374, 0074056, 0037276, 0034643, 0145376, 0001516, 0060636,
    0133630, 0173540, 0121344, 0155231, 0032513, 0005602, 0134516, 0007144,
    0131250, 0150540, 0075747, 0105341, 0027635, 0177020, 0012465, 0125402,
};
#endif
#ifdef IBMPC
static unsigned short BN[44] = {
    0x411e, 0x52fe, 0x495c, 0x3fe0, 0xb905, 0xdebc, 0x541c, 0xbfcf, 0x13c5,
    0x94e4, 0x1a4b, 0x3fb8, 0xa983, 0x633d, 0x6562, 0xbf96, 0xa9bd, 0x25eb,
    0xffee, 0x3f6d, 0x79ac, 0x4e54, 0xbc45, 0xbf3b, 0xd773, 0x1d28, 0xdb06,
    0x3f02, 0xfa5b, 0xd001, 0x015d, 0xbec2, 0x6991, 0xe501, 0x6d8b, 0x3e78,
    0x09f0, 0x4d97, 0xa3b1, 0xbe24, 0xb39e, 0xac32, 0xbfc2, 0x3dc3,
};
static unsigned short BD[40] = {
    /*0x0000,0x0000,0x0000,0x3ff0,*/
    0x47c7, 0x3f2d, 0x3808, 0xbfe4, 0x3c3e, 0x7517, 0x4c68, 0x3fce,
    0x122b, 0x0ed1, 0x3a7e, 0xbfab, 0xfb60, 0x53c1, 0x5e2e, 0x3f81,
    0xc7d8, 0x8f05, 0x105f, 0xbf4f, 0xcc34, 0xc069, 0x795f, 0x3f14,
    0x9b53, 0x145c, 0x1eec, 0xbed3, 0xc1cd, 0x5729, 0x6170, 0x3e89,
    0xf15c, 0x0f7c, 0x1a2c, 0xbe35, 0xb560, 0x02a6, 0xbfc2, 0x3dd3,
};
#endif
#ifdef MIEEE
static unsigned short BN[44] = {
    0x3fe0, 0x495c, 0x52fe, 0x411e, 0xbfcf, 0x541c, 0xdebc, 0xb905, 0x3fb8,
    0x1a4b, 0x94e4, 0x13c5, 0xbf96, 0x6562, 0x633d, 0xa983, 0x3f6d, 0xffee,
    0x25eb, 0xa9bd, 0xbf3b, 0xbc45, 0x4e54, 0x79ac, 0x3f02, 0xdb06, 0x1d28,
    0xd773, 0xbec2, 0x015d, 0xd001, 0xfa5b, 0x3e78, 0x6d8b, 0xe501, 0x6991,
    0xbe24, 0xa3b1, 0x4d97, 0x09f0, 0x3dc3, 0xbfc2, 0xac32, 0xb39e,
};
static unsigned short BD[40] = {
    /*0x3ff0,0x0000,0x0000,0x0000,*/
    0xbfe4, 0x3808, 0x3f2d, 0x47c7, 0x3fce, 0x4c68, 0x7517, 0x3c3e,
    0xbfab, 0x3a7e, 0x0ed1, 0x122b, 0x3f81, 0x5e2e, 0x53c1, 0xfb60,
    0xbf4f, 0x105f, 0x8f05, 0xc7d8, 0x3f14, 0x795f, 0xc069, 0xcc34,
    0xbed3, 0x1eec, 0x145c, 0x9b53, 0x3e89, 0x6170, 0x5729, 0xc1cd,
    0xbe35, 0x1a2c, 0x0f7c, 0xf15c, 0x3dd3, 0xbfc2, 0x02a6, 0xb560,
};
#endif

/* 6.25 to infinity */
#ifdef UNK
static double CN[5] = {
    -5.90592860534773254987E-1, 6.29235242724368800674E-1,
    -1.72858975380388136411E-1, 1.64837047825189632310E-2,
    -4.86827613020462700845E-4,
};
static double CD[5] = {
    /* 1.00000000000000000000E0,*/
    -2.69820057197544900361E0,  1.73270799045947845857E0,
    -3.93708582281939493482E-1, 3.44278924041233391079E-2,
    -9.73655226040941223894E-4,
};
#endif
#ifdef DEC
static unsigned short CN[20] = {
    0140027, 0030427, 0176477, 0074402, 0040041, 0012617, 0112375,
    0162657, 0137461, 0000761, 0074120, 0135160, 0036607, 0004325,
    0117246, 0115525, 0135377, 0036345, 0064750, 0047732,
};
static unsigned short CD[20] = {
    /*0040200,0000000,0000000,0000000,*/
    0140454, 0127521, 0071653, 0133415, 0040335, 0144540, 0016105,
    0045241, 0137711, 0112053, 0155034, 0062237, 0037015, 0002102,
    0177442, 0074546, 0135577, 0036345, 0064750, 0052152,
};
#endif
#ifdef IBMPC
static unsigned short CN[20] = {
    0xef20, 0xffa7, 0xe622, 0xbfe2, 0xbcb6, 0xf29f, 0x22b1,
    0x3fe4, 0x174e, 0x2f0a, 0x203e, 0xbfc6, 0xd36b, 0xb3d4,
    0xe11a, 0x3f90, 0x09fb, 0xad3d, 0xe79c, 0xbf3f,
};
static unsigned short CD[20] = {
    /*0x0000,0x0000,0x0000,0x3ff0,*/
    0x76e2, 0x2e75, 0x95ea, 0xc005, 0xa954, 0x0388, 0xb92c,
    0x3ffb, 0x8c94, 0x7b43, 0x3285, 0xbfd9, 0x4f2d, 0x5fe4,
    0xa088, 0x3fa1, 0x0a8d, 0xad3d, 0xe79c, 0xbf4f,
};
#endif
#ifdef MIEEE
static unsigned short CN[20] = {
    0xbfe2, 0xe622, 0xffa7, 0xef20, 0x3fe4, 0x22b1, 0xf29f,
    0xbcb6, 0xbfc6, 0x203e, 0x2f0a, 0x174e, 0x3f90, 0xe11a,
    0xb3d4, 0xd36b, 0xbf3f, 0xe79c, 0xad3d, 0x09fb,
};
static unsigned short CD[20] = {
    /*0x3ff0,0x0000,0x0000,0x0000,*/
    0xc005, 0x95ea, 0x2e75, 0x76e2, 0x3ffb, 0xb92c, 0x0388,
    0xa954, 0xbfd9, 0x3285, 0x7b43, 0x8c94, 0x3fa1, 0xa088,
    0x5fe4, 0x4f2d, 0xbf4f, 0xe79c, 0xad3d, 0x0a8d,
};
#endif

#ifdef ANSIPROT
extern double chbevl(double, void *, int);
extern double sqrt(double);
extern double fabs(double);
extern double polevl(double, void *, int);
extern double p1evl(double, void *, int);
#else
double chbevl(), sqrt(), fabs(), polevl(), p1evl();
#endif
extern double PI, MACHEP;

double dawsn(xx) double xx;
{
  double x, y;
  int sign;

  sign = 1;
  if (xx < 0.0) {
    sign = -1;
    xx = -xx;
  }

  if (xx < 3.25) {
    x = xx * xx;
    y = xx * polevl(x, AN, 9) / polevl(x, AD, 10);
    return (sign * y);
  }

  x = 1.0 / (xx * xx);

  if (xx < 6.25) {
    y = 1.0 / xx + x * polevl(x, BN, 10) / (p1evl(x, BD, 10) * xx);
    return (sign * 0.5 * y);
  }

  if (xx > 1.0e9)
    return ((sign * 0.5) / xx);

  /* 6.25 to infinity */
  y = 1.0 / xx + x * polevl(x, CN, 4) / (p1evl(x, CD, 5) * xx);
  return (sign * 0.5 * y);
}