replaced mathematical routines by our own

This commit is contained in:
ceriel 1988-07-25 11:26:26 +00:00
parent d443f370d2
commit 324c95ae62
5 changed files with 384 additions and 305 deletions

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@ -1,74 +1,102 @@
/*
* (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*
* Author: Ceriel J.H. Jacobs
*/
/* $Header$ */ /* $Header$ */
/* #include <math.h>
floating-point arctangent
atan returns the value of the arctangent of its
argument in the range [-pi/2,pi/2].
there are no error returns.
coefficients are #5077 from Hart & Cheney. (19.56D)
*/
static double sq2p1 = 2.414213562373095048802e0;
static double sq2m1 = .414213562373095048802e0;
static double pio2 = 1.570796326794896619231e0;
static double pio4 = .785398163397448309615e0;
static double p4 = .161536412982230228262e2;
static double p3 = .26842548195503973794141e3;
static double p2 = .11530293515404850115428136e4;
static double p1 = .178040631643319697105464587e4;
static double p0 = .89678597403663861959987488e3;
static double q4 = .5895697050844462222791e2;
static double q3 = .536265374031215315104235e3;
static double q2 = .16667838148816337184521798e4;
static double q1 = .207933497444540981287275926e4;
static double q0 = .89678597403663861962481162e3;
/*
xatan evaluates a series valid in the
range [-0.414...,+0.414...].
*/
static double
xatan(arg)
double arg;
{
double argsq;
double value;
argsq = arg*arg;
value = ((((p4*argsq + p3)*argsq + p2)*argsq + p1)*argsq + p0);
value = value/(((((argsq + q4)*argsq + q3)*argsq + q2)*argsq + q1)*argsq + q0);
return(value*arg);
}
static double
satan(arg)
double arg;
{
if(arg < sq2m1)
return(xatan(arg));
else if(arg > sq2p1)
return(pio2 - xatan(1/arg));
else
return(pio4 + xatan((arg-1)/(arg+1)));
}
/*
atan makes its argument positive and
calls the inner routine satan.
*/
double double
_atn(arg) _atn(x)
double arg; double x;
{ {
if(arg>0) /* The interval [0, infinity) is treated as follows:
return(satan(arg)); Define partition points Xi
else X0 = 0
return(-satan(-arg)); X1 = tan(pi/16)
X2 = tan(3pi/16)
X3 = tan(5pi/16)
X4 = tan(7pi/16)
X5 = infinity
and evaluation nodes xi
x2 = tan(2pi/16)
x3 = tan(4pi/16)
x4 = tan(6pi/16)
x5 = infinity
An argument x in [Xn-1, Xn] is now reduced to an argument
t in [-X1, X1] by the following formulas:
t = 1/xn - (1/(xn*xn) + 1)/((1/xn) + x)
arctan(x) = arctan(xi) + arctan(t)
For the interval [0, p/16] an approximation is used:
arctan(x) = x * P(x*x)/Q(x*x)
*/
static struct precomputed {
double X; /* partition point */
double arctan; /* arctan of evaluation node */
double one_o_x; /* 1 / xn */
double one_o_xsq_p_1; /* 1 / (xn*xn) + 1 */
} prec[5] = {
{ 0.19891236737965800691159762264467622,
0.0,
0.0, /* these don't matter */
0.0 } ,
{ 0.66817863791929891999775768652308076, /* tan(3pi/16) */
M_PI_8,
2.41421356237309504880168872420969808,
6.82842712474619009760337744841939616 },
{ 1.49660576266548901760113513494247691, /* tan(5pi/16) */
M_PI_4,
1.0,
2.0 },
{ 5.02733949212584810451497507106407238, /* tan(7pi/16) */
M_3PI_8,
0.41421356237309504880168872420969808,
1.17157287525380998659662255158060384 },
{ MAXDOUBLE,
M_PI_2,
0.0,
1.0 }};
/* Hart & Cheney # 5037 */
static double p[5] = {
0.7698297257888171026986294745e+03,
0.1557282793158363491416585283e+04,
0.1033384651675161628243434662e+04,
0.2485841954911840502660889866e+03,
0.1566564964979791769948970100e+02
};
static double q[6] = {
0.7698297257888171026986294911e+03,
0.1813892701754635858982709369e+04,
0.1484049607102276827437401170e+04,
0.4904645326203706217748848797e+03,
0.5593479839280348664778328000e+02,
0.1000000000000000000000000000e+01
};
int negative = x < 0.0;
register struct precomputed *pr = prec;
if (negative) {
x = -x;
}
while (x > pr->X) pr++;
if (pr != prec) {
x = pr->arctan +
atan(pr->one_o_x - pr->one_o_xsq_p_1/(pr->one_o_x + x));
}
else {
double xsq = x*x;
x = x * POLYNOM4(xsq, p)/POLYNOM5(xsq, q);
}
return negative ? -x : x;
} }

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/*
* (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*
* Author: Ceriel J.H. Jacobs
*/
/* $Header$ */ /* $Header$ */
#include <pc_err.h> #include <math.h>
#include <pc_err.h>
extern double _fif(); extern _trp();
extern double _fef();
extern _trp();
/*
exp returns the exponential function of its
floating-point argument.
The coefficients are #1069 from Hart and Cheney. (22.35D)
*/
#define HUGE 1.701411733192644270e38
static double p0 = .2080384346694663001443843411e7;
static double p1 = .3028697169744036299076048876e5;
static double p2 = .6061485330061080841615584556e2;
static double q0 = .6002720360238832528230907598e7;
static double q1 = .3277251518082914423057964422e6;
static double q2 = .1749287689093076403844945335e4;
static double log2e = 1.4426950408889634073599247;
static double sqrt2 = 1.4142135623730950488016887;
static double maxf = 10000.0;
static double static double
floor(d) floor(x)
double d; double x;
{ {
if (d<0) { extern double _fif();
d = -d; double val;
if (_fif(d, 1.0, &d) != 0)
d += 1; return _fif(x, 1,0, &val) < 0 ? val - 1.0 : val ;
d = -d; /* this also works if _fif always returns a positive
} else fractional part
_fif(d, 1.0, &d); */
return(d);
} }
static double static double
ldexp(fr,exp) ldexp(fl,exp)
double fr; double fl;
int exp; int exp;
{ {
int neg,i; extern double _fef();
int sign = 1;
int currexp;
neg = 1; if (fl<0) {
if (fr < 0) { fl = -fl;
fr = -fr; sign = -1;
neg = -1;
} }
fr = _fef(fr, &i); fl = _fef(fl,&currexp);
/* exp += currexp;
while (fr < 0.5) { if (exp > 0) {
fr *= 2; while (exp>30) {
exp--; fl *= (double) (1L << 30);
exp -= 30;
}
fl *= (double) (1L << exp);
} }
*/ else {
exp += i; while (exp<-30) {
if (exp > 127) { fl /= (double) (1L << 30);
_trp(EEXP); exp += 30;
return(neg * HUGE); }
fl /= (double) (1L << -exp);
} }
if (exp < -127) return sign * fl;
return(0);
while (exp > 14) {
fr *= (1<<14);
exp -= 14;
}
while (exp < -14) {
fr /= (1<<14);
exp += 14;
}
if (exp > 0)
fr *= (1<<exp);
if (exp < 0)
fr /= (1<<(-exp));
return(neg * fr);
} }
double double
_exp(arg) _exp(x)
double arg; double x;
{ {
double fract; /* 2**x = (Q(x*x)+x*P(x*x))/(Q(x*x)-x*P(x*x)) for x in [0,0.5] */
double temp1, temp2, xsq; /* Hart & Cheney #1069 */
int ent;
if(arg == 0) static double p[3] = {
return(1); 0.2080384346694663001443843411e+07,
if(arg < -maxf) 0.3028697169744036299076048876e+05,
return(0); 0.6061485330061080841615584556e+02
if(arg > maxf) { };
_trp(EEXP);
return(HUGE); static double q[4] = {
0.6002720360238832528230907598e+07,
0.3277251518082914423057964422e+06,
0.1749287689093076403844945335e+04,
0.1000000000000000000000000000e+01
};
int negative = x < 0;
int ipart, large = 0;
double xsqr, xPxx, Qxx;
if (x < M_LN_MIN_D) {
return M_MIN_D;
} }
arg *= log2e; if (x >= M_LN_MAX_D) {
ent = floor(arg); if (x > M_LN_MAX_D) {
fract = (arg-ent) - 0.5; _trp(EEXP);
xsq = fract*fract; return HUGE;
temp1 = ((p2*xsq+p1)*xsq+p0)*fract; }
temp2 = ((xsq+q2)*xsq+q1)*xsq + q0; return M_MAX_D;
return(ldexp(sqrt2*(temp2+temp1)/(temp2-temp1), ent)); }
if (negative) {
x = -x;
}
x /= M_LN2;
ipart = floor(x);
x -= ipart;
if (x > 0.5) {
large = 1;
x -= 0.5;
}
xsqr = x * x;
xPxx = x * POLYNOM2(xsqr, p);
Qxx = POLYNOM3(xsqr, q);
x = (Qxx + xPxx) / (Qxx - xPxx);
if (large) x *= M_SQRT2;
x = ldexp(x, ipart);
if (negative) return 1.0/x;
return x;
} }

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/*
* (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*
* Author: Ceriel J.H. Jacobs
*/
/* $Header$ */ /* $Header$ */
#include <pc_err.h> #include <math.h>
#include <pc_err.h>
extern double _fef(); extern _trp();
extern _trp();
/*
log returns the natural logarithm of its floating
point argument.
The coefficients are #2705 from Hart & Cheney. (19.38D)
It calls _fef.
*/
#define HUGE 1.701411733192644270e38
static double log2 = 0.693147180559945309e0;
static double sqrto2 = 0.707106781186547524e0;
static double p0 = -.240139179559210510e2;
static double p1 = 0.309572928215376501e2;
static double p2 = -.963769093368686593e1;
static double p3 = 0.421087371217979714e0;
static double q0 = -.120069589779605255e2;
static double q1 = 0.194809660700889731e2;
static double q2 = -.891110902798312337e1;
double double
_log(arg) _log(x)
double arg; double x;
{ {
double x,z, zsq, temp; /* log(x) = z*P(z*z)/Q(z*z), z = (x-1)/(x+1), x in [1/sqrt(2), sqrt(2)]
int exp;
if(arg <= 0) {
_trp(ELOG);
return(-HUGE);
}
x = _fef(arg,&exp);
/*
while(x < 0.5) {
x =* 2;
exp--;
}
*/ */
if(x<sqrto2) { /* Hart & Cheney #2707 */
x *= 2;
exp--; static double p[5] = {
0.7504094990777122217455611007e+02,
-0.1345669115050430235318253537e+03,
0.7413719213248602512779336470e+02,
-0.1277249755012330819984385000e+02,
0.3327108381087686938144000000e+00
};
static double q[5] = {
0.3752047495388561108727775374e+02,
-0.7979028073715004879439951583e+02,
0.5616126132118257292058560360e+02,
-0.1450868091858082685362325000e+02,
0.1000000000000000000000000000e+01
};
extern double _fef();
double z, zsqr;
int exponent;
if (x <= 0) {
_trp(ELOG);
return -HUGE;
} }
x = _fef(x, &exponent);
while (x < M_1_SQRT2) {
x += x;
exponent--;
}
z = (x-1)/(x+1); z = (x-1)/(x+1);
zsq = z*z; zsqr = z*z;
return z * POLYNOM4(zsqr, p) / POLYNOM4(zsqr, q) + exponent * M_LN2;
temp = ((p3*zsq + p2)*zsq + p1)*zsq + p0;
temp = temp/(((zsq + q2)*zsq + q1)*zsq + q0);
temp = temp*z + exp*log2;
return(temp);
} }

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/*
* (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*
* Author: Ceriel J.H. Jacobs
*/
/* $Header$ */ /* $Header$ */
extern double _fif(); #include <math.h>
/*
C program for floating point sin/cos.
Calls _fif.
There are no error exits.
Coefficients are #3370 from Hart & Cheney (18.80D).
*/
static double twoopi = 0.63661977236758134308;
static double p0 = .1357884097877375669092680e8;
static double p1 = -.4942908100902844161158627e7;
static double p2 = .4401030535375266501944918e6;
static double p3 = -.1384727249982452873054457e5;
static double p4 = .1459688406665768722226959e3;
static double q0 = .8644558652922534429915149e7;
static double q1 = .4081792252343299749395779e6;
static double q2 = .9463096101538208180571257e4;
static double q3 = .1326534908786136358911494e3;
static double static double
sinus(arg, quad) sinus(x, quadrant)
double arg; double x;
int quad;
{ {
double e, f; /* sin(0.5*pi*x) = x * P(x*x)/Q(x*x) for x in [0,1] */
double ysq; /* Hart & Cheney # 3374 */
double x,y;
int k;
double temp1, temp2;
x = arg; static double p[6] = {
if(x<0) { 0.4857791909822798473837058825e+10,
-0.1808816670894030772075877725e+10,
0.1724314784722489597789244188e+09,
-0.6351331748520454245913645971e+07,
0.1002087631419532326179108883e+06,
-0.5830988897678192576148973679e+03
};
static double q[6] = {
0.3092566379840468199410228418e+10,
0.1202384907680254190870913060e+09,
0.2321427631602460953669856368e+07,
0.2848331644063908832127222835e+05,
0.2287602116741682420054505174e+03,
0.1000000000000000000000000000e+01
};
double xsqr;
int t;
if (x < 0) {
quadrant += 2;
x = -x; x = -x;
quad = quad + 2;
} }
x = x*twoopi; /*underflow?*/ if (M_PI_2 - x == M_PI_2) {
if(x>32764){ switch(quadrant) {
y = _fif(x, 10.0, &e); case 0:
e = e + quad; case 2:
_fif(0.25, e, &f); return 0.0;
quad = e - 4*f; case 1:
}else{ return 1.0;
k = x; case 3:
y = x - k; return -1.0;
quad = (quad + k) & 03; }
} }
if (quad & 01) if (x >= M_2PI) {
y = 1-y; if (x <= 0x7fffffff) {
if(quad > 1) /* Use extended precision to calculate reduced argument.
y = -y; Split 2pi in 2 parts a1 and a2, of which the first only
uses some bits of the mantissa, so that n * a1 is
exactly representable, where n is the integer part of
x/pi.
Here we used 12 bits of the mantissa for a1.
Also split x in integer part x1 and fraction part x2.
We then compute x-n*2pi as ((x1 - n*a1) + x2) - n*a2.
*/
#define A1 6.2822265625
#define A2 0.00095874467958647692528676655900576
double n = (long) (x / M_2PI);
double x1 = (long) x;
double x2 = x - x1;
x = x1 - n * A1;
x += x2;
x -= n * A2;
#undef A1
#undef A2
}
else {
extern double _fif();
double dummy;
ysq = y*y; x = _fif(x/M_2PI, 1.0, &dummy) * M_2PI;
temp1 = ((((p4*ysq+p3)*ysq+p2)*ysq+p1)*ysq+p0)*y; }
temp2 = ((((ysq+q3)*ysq+q2)*ysq+q1)*ysq+q0); }
return(temp1/temp2); x /= M_PI_2;
t = x;
x -= t;
quadrant = (quadrant + (int)(t % 4)) % 4;
if (quadrant & 01) {
x = 1 - x;
}
if (quadrant > 1) {
x = -x;
}
xsqr = x * x;
x = x * POLYNOM5(xsqr, p) / POLYNOM5(xsqr, q);
return x;
} }
double double
_cos(arg) _sin(x)
double arg; double x;
{ {
if(arg<0) return sinus(x, 0);
arg = -arg;
return(sinus(arg, 1));
} }
double double
_sin(arg) _cos(x)
double arg; double x;
{ {
return(sinus(arg, 0)); if (x < 0) x = -x;
return sinus(x, 1);
} }

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/*
* (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*
* Author: Ceriel J.H. Jacobs
*/
/* $Header$ */ /* $Header$ */
#include <pc_err.h> #include <math.h>
#include <pc_err.h>
extern _trp();
extern double _fef(); #define NITER 5
extern _trp();
/* static double
sqrt returns the square root of its floating ldexp(fl,exp)
point argument. Newton's method. double fl;
int exp;
{
extern double _fef();
int sign = 1;
int currexp;
calls _fef if (fl<0) {
*/ fl = -fl;
sign = -1;
}
fl = _fef(fl,&currexp);
exp += currexp;
if (exp > 0) {
while (exp>30) {
fl *= (double) (1L << 30);
exp -= 30;
}
fl *= (double) (1L << exp);
}
else {
while (exp<-30) {
fl /= (double) (1L << 30);
exp += 30;
}
fl /= (double) (1L << -exp);
}
return sign * fl;
}
double double
_sqt(arg) _sqt(x)
double arg; double x;
{ {
double x, temp; extern double _fef();
int exp; int exponent;
int i; double val;
if(arg <= 0) { if (x <= 0) {
if(arg < 0) if (x < 0) _trp(ESQT);
_trp(ESQT); return 0;
return(0);
} }
x = _fef(arg,&exp);
/*
while(x < 0.5) {
x =* 2;
exp--;
}
*/
/*
* NOTE
* this wont work on 1's comp
*/
if(exp & 1) {
x *= 2;
exp--;
}
temp = 0.5*(1 + x);
while(exp > 28) { val = _fef(x, &exponent);
temp *= (1<<14); if (exponent & 1) {
exp -= 28; exponent--;
val *= 2;
} }
while(exp < -28) { val = ldexp(val + 1.0, exponent/2 - 1);
temp /= (1<<14); /* was: val = (val + 1.0)/2.0; val = ldexp(val, exponent/2); */
exp += 28; for (exponent = NITER - 1; exponent >= 0; exponent--) {
val = (val + x / val) / 2.0;
} }
if(exp >= 0) return val;
temp *= 1 << (exp/2);
else
temp /= 1 << (-exp/2);
for(i=0; i<=4; i++)
temp = 0.5*(temp + arg/temp);
return(temp);
} }