Cloned SEACAS for EXODUS library with extra build files for internal package management.
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#ifndef WINMATH_H
#define WINMATH_H
/**********************************************************************
acosh.c -
$Author$
$Date$
created at: Fri Apr 12 00:34:17 JST 2002
public domain rewrite of acosh(3), asinh(3) and atanh(3)
**********************************************************************/
#include <errno.h>
#include <float.h>
#include <math.h>
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
/* DBL_MANT_DIG must be less than 4 times of bits of int */
#ifndef DBL_MANT_DIG
#define DBL_MANT_DIG 53 /* in this case, at least 12 digit precision */
#endif
#define BIG_CRITERIA_BIT (1<<DBL_MANT_DIG/2)
#if BIG_CRITERIA_BIT > 0
#define BIG_CRITERIA (1.0*BIG_CRITERIA_BIT)
#else
#define BIG_CRITERIA (1.0*(1<<DBL_MANT_DIG/4)*(1<<(DBL_MANT_DIG/2+1-DBL_MANT_DIG/4)))
#endif
#define SMALL_CRITERIA_BIT (1<<(DBL_MANT_DIG/3))
#if SMALL_CRITERIA_BIT > 0
#define SMALL_CRITERIA (1.0/SMALL_CRITERIA_BIT)
#else
#define SMALL_CRITERIA (1.0*(1<<DBL_MANT_DIG/4)*(1<<(DBL_MANT_DIG/3+1-DBL_MANT_DIG/4)))
#endif
inline double acosh(double x)
{
if (x < 1)
x = -1; /* NaN */
else if (x == 1)
return 0;
else if (x > BIG_CRITERIA)
x += x;
else
x += sqrt((x + 1) * (x - 1));
return log(x);
}
inline double asinh(double x)
{
int neg = x < 0;
double z = fabs(x);
if (z < SMALL_CRITERIA) return x;
if (z < (1.0/(1<<DBL_MANT_DIG/5))) {
double x2 = z * z;
z *= 1 + x2 * (-1.0/6.0 + x2 * 3.0/40.0);
}
else if (z > BIG_CRITERIA) {
z = log(z + z);
}
else {
z = log(z + sqrt(z * z + 1));
}
if (neg) z = -z;
return z;
}
inline double atanh(double x)
{
int neg = x < 0;
double z = fabs(x);
if (z < SMALL_CRITERIA) return x;
z = log(z > 1 ? -1 : (1 + z) / (1 - z)) / 2;
if (neg) z = -z;
return z;
}
inline double round(double val)
{
return floor(val + 0.5);
}
inline void srand48(double seed)
{
srand(seed);
}
inline double drand48()
{
return (double(rand()) / RAND_MAX);
}
inline float tgammaf(float z){
static unsigned int c = 9;
static float lanczos_coefficients[] = {1.000000000000000174663f,
5716.400188274341379136f,
-14815.30426768413909044f,
14291.49277657478554025f,
-6348.160217641458813289f,
1301.608286058321874105f,
-108.1767053514369634679f,
2.605696505611755827729f,
-0.7423452510201416151527e-2f,
0.5384136432509564062961e-7f,
-0.4023533141268236372067e-8f
};
float return_val = 0.0f;
z -= 1.0f;
float temp = z + c + 0.5f;
float A = lanczos_coefficients[0];
int i = 0;
for(i = 1; i < c+2; ++i){
A += lanczos_coefficients[i]/(z+i);
}
return_val = sqrt(2 * M_PI)* pow(temp, z + 0.5f) * exp(-temp) * A;
return return_val;
}
inline double tgamma(double z){
static unsigned int c = 9;
static double lanczos_coefficients[] = {1.000000000000000174663,
5716.400188274341379136,
-14815.30426768413909044,
14291.49277657478554025,
-6348.160217641458813289,
1301.608286058321874105,
-108.1767053514369634679,
2.605696505611755827729,
-0.7423452510201416151527e-2,
0.5384136432509564062961e-7,
-0.4023533141268236372067e-8
};
double return_val = 0.0;
z -= 1.0;
double temp = z + c + 0.5;
double A = lanczos_coefficients[0];
int i = 0;
for(i = 1; i < c+2; ++i){
A += lanczos_coefficients[i]/(z+i);
}
return_val = sqrt(2 * M_PI)* pow(temp, z + 0.5) * exp(-temp) * A;
return return_val;
}
inline long double tgammal(long double z){
static unsigned int c = 9;
static long double lanczos_coefficients[] = {1.000000000000000174663,
5716.400188274341379136,
-14815.30426768413909044,
14291.49277657478554025,
-6348.160217641458813289,
1301.608286058321874105,
-108.1767053514369634679,
2.605696505611755827729,
-0.7423452510201416151527e-2,
0.5384136432509564062961e-7,
-0.4023533141268236372067e-8
};
long double return_val = 0.0;
z -= 1.0;
long double temp = z + c + 0.5;
long double A = lanczos_coefficients[0];
int i = 0;
for(i = 1; i < c+2; ++i){
A += lanczos_coefficients[i]/(z+i);
}
return_val = sqrt(2 * M_PI)* pow(temp, z + 0.5) * exp(-temp) * A;
return return_val;
}
// This function was adapted from a public domain implementation of erf
// which is available at http://www.johndcook.com/cpp_erf.html. The only
// changes made were to change the type from double to float.
inline float erff(float x)
{
// constants
float a1 = 0.254829592f;
float a2 = -0.284496736f;
float a3 = 1.421413741f;
float a4 = -1.453152027f;
float a5 = 1.061405429f;
float p = 0.3275911f;
// Save the sign of x
int sign = 1;
if (x < 0)
sign = -1;
x = fabs(x);
// A&S formula 7.1.26
float t = 1.0f/(1.0f + p*x);
float y = 1.0f - (((((a5*t + a4)*t) + a3)*t + a2)*t + a1)*t*exp(-x*x);
return sign*y;
}
#endif