Initial revision

This commit is contained in:
ceriel 1988-07-22 16:53:29 +00:00
parent 8524608cf3
commit a18fcb9048
23 changed files with 1759 additions and 0 deletions

22
lang/cem/libcc/math/LIST Normal file
View file

@ -0,0 +1,22 @@
tail_m.a
asin.c
atan2.c
atan.c
ceil.c
cosh.c
fabs.c
gamma.c
hypot.c
jn.c
j0.c
j1.c
log10.c
pow.c
log.c
sin.c
sinh.c
sqrt.c
tan.c
tanh.c
exp.c
floor.c

View file

@ -0,0 +1,53 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
extern int errno;
static double
asin_acos(x, cosfl)
double x;
{
int negative = x < 0;
extern double sqrt(), atan();
if (negative) {
x = -x;
}
if (x > 1) {
errno = EDOM;
return 0;
}
if (x == 1) {
x = M_PI_2;
}
else x = atan(x/sqrt(1-x*x));
if (negative) x = -x;
if (cosfl) {
return M_PI_2 - x;
}
return x;
}
double
asin(x)
double x;
{
return asin_acos(x, 0);
}
double
acos(x)
double x;
{
return asin_acos(x, 1);
}

103
lang/cem/libcc/math/atan.c Normal file
View file

@ -0,0 +1,103 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
double
atan(x)
double x;
{
/* The interval [0, infinity) is treated as follows:
Define partition points Xi
X0 = 0
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;
}

View file

@ -0,0 +1,46 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
extern int errno;
double
atan2(y, x)
double x, y;
{
extern double atan();
double absx, absy, val;
if (x == 0 && y == 0) {
errno = EDOM;
return 0;
}
absy = y < 0 ? -y : y;
absx = x < 0 ? -x : x;
if (absy - absx == absy) {
/* x negligible compared to y */
return y < 0 ? -M_PI_2 : M_PI_2;
}
if (absx - absy == absx) {
/* y negligible compared to x */
val = 0.0;
}
else val = atan(y/x);
if (x > 0) {
/* first or fourth quadrant; already correct */
return val;
}
if (y < 0) {
/* third quadrant */
return val - M_PI;
}
return val + M_PI;
}

View file

@ -0,0 +1,21 @@
/*
* (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
*/
/* $Header$ */
double
ceil(x)
double x;
{
extern double modf();
double val;
return modf(x, &val) > 0 ? val + 1.0 : val ;
/* this also works if modf always returns a positive
fractional part
*/
}

View file

@ -0,0 +1,38 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
extern int errno;
double
cosh(x)
double x;
{
extern double exp();
if (x < 0) {
x = -x;
}
if (x > M_LN_MAX_D) {
/* exp(x) would overflow */
if (x >= M_LN_MAX_D + M_LN2) {
/* not representable */
x = HUGE;
errno = ERANGE;
}
else x = exp (x - M_LN2);
}
else {
double expx = exp(x);
x = 0.5 * (expx + 1.0/expx);
}
return x;
}

67
lang/cem/libcc/math/exp.c Normal file
View file

@ -0,0 +1,67 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
extern int errno;
double
exp(x)
double x;
{
/* 2**x = (Q(x*x)+x*P(x*x))/(Q(x*x)-x*P(x*x)) for x in [0,0.5] */
/* Hart & Cheney #1069 */
static double p[3] = {
0.2080384346694663001443843411e+07,
0.3028697169744036299076048876e+05,
0.6061485330061080841615584556e+02
};
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;
extern double floor(), ldexp();
if (x <= M_LN_MIN_D) {
if (x < M_LN_MIN_D) errno = ERANGE;
return M_MIN_D;
}
if (x >= M_LN_MAX_D) {
if (x < M_LN_MAX_D) errno = ERANGE;
return M_MAX_D;
}
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;
}

View file

@ -0,0 +1,15 @@
/*
* (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
*/
/* $Header$ */
double
fabs(x)
double x;
{
return x < 0 ? -x : x;
}

View file

@ -0,0 +1,21 @@
/*
* (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
*/
/* $Header$ */
double
floor(x)
double x;
{
extern double modf();
double val;
return modf(x, &val) < 0 ? val - 1.0 : val ;
/* this also works if modf always returns a positive
fractional part
*/
}

137
lang/cem/libcc/math/gamma.c Normal file
View file

@ -0,0 +1,137 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
static double
smallpos_gamma(x)
double x;
{
/* Approximation of gamma function using
gamma(x) = P(x-2) / Q(x-2) for x in [2,3]
*/
/* Hart & Cheney # 5251 */
static double p[11] = {
-0.2983543278574342138830437659e+06,
-0.2384953970018198872468734423e+06,
-0.1170494760121780688403854445e+06,
-0.3949445048301571936421824091e+05,
-0.1046699423827521405330650531e+05,
-0.2188218110071816359394795998e+04,
-0.3805112208641734657584922631e+03,
-0.5283123755635845383718978382e+02,
-0.6128571763704498306889428212e+01,
-0.5028018054416812467364198750e+00,
-0.3343060322330595274515660112e-01
};
static double q[9] = {
-0.2983543278574342138830438524e+06,
-0.1123558608748644911342306408e+06,
0.5332716689118142157485686311e+05,
0.8571160498907043851961147763e+04,
-0.4734865977028211706556819770e+04,
0.1960497612885585838997039621e+03,
0.1257733367869888645966647426e+03,
-0.2053126153100672764513929067e+02,
0.1000000000000000000000000000e+01
};
double result = 1.0;
while (x > 3) {
x -= 1.0;
result *= x;
}
while (x < 2) {
result /= x;
x += 1.0;
}
x -= 2.0;
return result * POLYNOM10(x, p) / POLYNOM8(x, q);
}
#define log_sqrt_2pi 0.91893853320467274178032973640561763
int signgam;
static double
bigpos_loggamma(x)
double x;
{
/* computes the log(gamma(x)) function for big arguments
using the Stirling form
log(gamma(x)) = (x - 0.5)log(x) - x + log(sqrt(2*pi)) + fi(x)
where fi(x) = (1/x)*P(1/(x*x))/Q(1/(x*x)) for x in [12,1000]
*/
/* Hart & Cheney # 5468 */
static double p[4] = {
0.12398282342474941538685913e+00,
0.67082783834332134961461700e+00,
0.64507302912892202513890000e+00,
0.66662907040200752600000000e-01
};
static double q[4] = {
0.14877938810969929846815600e+01,
0.80995271894897557472821400e+01,
0.79966911236636441947720000e+01,
0.10000000000000000000000000e+01
};
double rsq = 1.0/(x*x);
extern double log();
return (x-0.5)*log(x)-x+log_sqrt_2pi+POLYNOM3(rsq, p)/(x*POLYNOM3(rsq, q));
}
static double
neg_loggamma(x)
double x;
{
/* compute the log(gamma(x)) function for negative values of x,
using the rule:
-x*gamma(x)*gamma(-x) = pi/sin(z*pi)
*/
extern double sin(), log();
double sinpix;
x = -x;
sinpix = sin(M_PI * x);
if (sinpix == 0.0) {
errno = EDOM;
return HUGE;
}
if (sinpix < 0) sinpix = -sinpix;
else signgam = -1;
return log(M_PI/(x * smallpos_gamma(x) * sinpix));
}
double
gamma(x)
double x;
{
/* Wrong name; Actually computes log(gamma(x))
*/
extern double log();
signgam = 1;
if (x <= 0) {
return neg_loggamma(x);
}
if (x > 12.0) {
return bigpos_loggamma(x);
}
return log(smallpos_gamma(x));
}

View file

@ -0,0 +1,39 @@
/*
* (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
*/
/* $Header$ */
double
hypot(x,y)
double x,y;
{
/* Computes sqrt(x*x+y*y), avoiding overflow */
extern double sqrt();
if (x < 0) x = -x;
if (y < 0) y = -y;
if (x > y) {
double t = y;
y = x;
x = t;
}
/* sqrt(x*x+y*y) = sqrt(y*y*(x*x/(y*y)+1.0)) = y*sqrt(x*x/(y*y)+1.0) */
x /= y;
return y*sqrt(x*x+1.0);
}
struct complex {
double r,i;
};
double
cabs(p_compl)
struct complex p_compl;
{
return hypot(p_compl.r, p_compl.i);
}

203
lang/cem/libcc/math/j0.c Normal file
View file

@ -0,0 +1,203 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
static double
P0(x)
double x;
{
/* P0(x) = P(z*z)/Q(z*z) where z = 8/x, with x >= 8 */
/* Hart & Cheney # 6554 */
static double p[9] = {
0.9999999999999999999999995647e+00,
0.5638253933310769952531889297e+01,
0.1124846237418285392887270013e+02,
0.1009280644639441488899111404e+02,
0.4290591487686900980651458361e+01,
0.8374209971661497198619102718e+00,
0.6702347074465611456598882534e-01,
0.1696260729396856143084502774e-02,
0.6463970103128382090713889584e-05
};
static double q[9] = {
0.9999999999999999999999999999e+00,
0.5639352566123269952531467562e+01,
0.1125463057106955935416066535e+02,
0.1010501892629524191262518048e+02,
0.4301396985171094350444425443e+01,
0.8418926086780046799127094223e+00,
0.6784915305473610998681570734e-01,
0.1754416614608056207958880988e-02,
0.7482977995134121064747276923e-05
};
double zsq = 64.0/(x*x);
return POLYNOM8(zsq, p) / POLYNOM8(zsq, q);
}
static double
Q0(x)
double x;
{
/* Q0(x) = z*P(z*z)/Q(z*z) where z = 8/x, x >= 8 */
/* Hart & Cheney # 6955 */
/* Probably typerror in Hart & Cheney; it sais:
Q0(x) = x*P(z*z)/Q(z*z)
*/
static double p[9] = {
-0.1562499999999999999999995808e-01,
-0.1111285583113679178917024959e+00,
-0.2877685516355036842789761274e+00,
-0.3477683453166454475665803194e+00,
-0.2093031978191084473537206358e+00,
-0.6209520943730206312601003832e-01,
-0.8434508346572023650653353729e-02,
-0.4414848186188819989871882393e-03,
-0.5768946278415631134804064871e-05
};
static double q[10] = {
0.9999999999999999999999999999e+00,
0.7121383005365046745065850254e+01,
0.1848194194302368046679068851e+02,
0.2242327522435983712994071530e+02,
0.1359286169255959339963319677e+02,
0.4089489268101204780080944780e+01,
0.5722140925672174525430730669e+00,
0.3219814230905924725810683346e-01,
0.5299687475496044642364124073e-03,
0.9423249021001925212258428217e-06
};
double zsq = 64.0/(x*x);
return (8.0/x) * POLYNOM8(zsq, p) / POLYNOM9(zsq, q);
}
static double
smallj0(x)
double x;
{
/* J0(x) = P(x*x)/Q(x*x) for x in [0,8] */
/* Hart & Cheney # 5852 */
static double p[10] = {
0.1641556014884554385346147435e+25,
-0.3943559664767296636012616471e+24,
0.2172018385924539313982287997e+23,
-0.4814859952069817648285245941e+21,
0.5345457598841972345381674607e+19,
-0.3301538925689637686465426220e+17,
0.1187390681211042949874031474e+15,
-0.2479851167896144439689877514e+12,
0.2803148940831953934479400118e+09,
-0.1336625500481224741885945416e+06
};
static double q[10] = {
0.1641556014884554385346137617e+25,
0.1603303724440893273539045602e+23,
0.7913043777646405204323616203e+20,
0.2613165313325153278086066185e+18,
0.6429607918826017759289213100e+15,
0.1237672982083407903483177730e+13,
0.1893012093677918995179541438e+10,
0.2263381356781110003609399116e+07,
0.1974019272727281783930443513e+04,
0.1000000000000000000000000000e+01
};
double xsq = x*x;
return POLYNOM9(xsq, p) / POLYNOM9(xsq, q);
}
double
j0(x)
double x;
{
/* Use J0(x) = sqrt(2/(pi*x))*(P0(x)*cos(X0)-Q0(x)*sin(X0))
where X0 = x - pi/4 for |x| > 8.
Use J0(-x) = J0(x).
Use direct approximation of smallj0 for |x| <= 8.
*/
extern double sqrt(), sin(), cos();
if (x < 0) x = -x;
if (x > 8.0) {
double X0 = x - M_PI_4;
return sqrt(M_2_PI/x)*(P0(x)*cos(X0) - Q0(x)*sin(X0));
}
return smallj0(x);
}
static double
smally0_bar(x)
double x;
{
/* Y0(x) = Y0BAR(x)+(2/pi)*J0(x)ln(x)
Approximation of Y0BAR for 0 <= x <= 8:
Y0BAR(x) = P(x*x)/Q(x*x)
Hart & Cheney #6250
*/
static double p[14] = {
-0.2692670958801060448840356941e+14,
0.6467231173109037044444917683e+14,
-0.5563036156275660297303897296e+13,
0.1698403391975239335187832821e+12,
-0.2606282788256139370857687880e+10,
0.2352841334491277505699488812e+08,
-0.1365184412186963659690851354e+06,
0.5371538422626582142170627457e+03,
-0.1478903875146718839145348490e+01,
0.2887840299886172125955719069e-02,
-0.3977426824263991024666116123e-05,
0.3738169731655229006655176866e-08,
-0.2194460874896856106887900645e-11,
0.6208996973821484304384239393e-15
};
static double q[6] = {
0.3648393301278364629844168660e+15,
0.1698390180526960997295118328e+13,
0.3587111679107612117789088586e+10,
0.4337760840406994515845890005e+07,
0.3037977771964348276793136205e+04,
0.1000000000000000000000000000e+01
};
double xsq = x*x;
return POLYNOM13(xsq, p) / POLYNOM5(xsq, q);
}
double
y0(x)
double x;
{
extern double sqrt(), sin(), cos(), log();
if (x <= 0.0) {
errno = EDOM;
return -HUGE;
}
if (x > 8.0) {
double X0 = x - M_PI_4;
return sqrt(M_2_PI/x) * (P0(x)*sin(X0)+Q0(x)*cos(X0));
}
return smally0_bar(x) + M_2_PI*j0(x)*log(x);
}

206
lang/cem/libcc/math/j1.c Normal file
View file

@ -0,0 +1,206 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
static double
P1(x)
double x;
{
/* P1(x) = P(z*z)/Q(z*z) where z = 8/x, with x >= 8 */
/* Hart & Cheney # 6755 */
static double p[9] = {
0.1000000000000000000000000489e+01,
0.5581663300347182292169450071e+01,
0.1100186625131173123750501118e+02,
0.9727139359130463694593683431e+01,
0.4060011483142278994462590992e+01,
0.7742832212665311906917358099e+00,
0.6021617752811098752098248630e-01,
0.1482350677236405118074646993e-02,
0.6094215148131061431667573909e-05
};
static double q[9] = {
0.9999999999999999999999999999e+00,
0.5579832245659682292169922224e+01,
0.1099168447731617288972771040e+02,
0.9707206835125961446797916892e+01,
0.4042610016540342097334497865e+01,
0.7671965204303836019508430169e+00,
0.5893258668794493100786371406e-01,
0.1393993644981256852404222530e-02,
0.4585597769784750669754696825e-05
};
double zsq = 64.0/(x*x);
return POLYNOM8(zsq, p) / POLYNOM8(zsq, q);
}
static double
Q1(x)
double x;
{
/* Q1(x) = z*P(z*z)/Q(z*z) where z = 8/x, x >= 8 */
/* Hart & Cheney # 7157 */
/* Probably typerror in Hart & Cheney; it sais:
Q1(x) = x*P(z*z)/Q(z*z)
*/
static double p[9] = {
0.4687499999999999999999995275e-01,
0.3302394516691663879252493748e+00,
0.8456888491208195767613862428e+00,
0.1008551084218946085420665147e+01,
0.5973407972399900690521296181e+00,
0.1737697433393258207540273097e+00,
0.2303862814819568573893610740e-01,
0.1171224207976250587945594946e-02,
0.1486418220337492918307904804e-04
};
static double q[10] = {
0.9999999999999999999999999999e+00,
0.7049380763213049609070823421e+01,
0.1807129960468949760845562209e+02,
0.2159171174362827330505421695e+02,
0.1283239297740546866114600499e+02,
0.3758349275324260869598403931e+01,
0.5055985453754739528620657666e+00,
0.2665604326323907148063400439e-01,
0.3821140353404633025596424652e-03,
0.3206696590241261037875154062e-06
};
double zsq = 64.0/(x*x);
return (8.0/x) * POLYNOM8(zsq, p) / POLYNOM9(zsq, q);
}
static double
smallj1(x)
double x;
{
/* J1(x) = x*P(x*x)/Q(x*x) for x in [0,8] */
/* Hart & Cheney # 6054 */
static double p[10] = {
0.1921176307760798128049021316e+25,
-0.2226092031387396254771375773e+24,
0.7894463902082476734673226741e+22,
-0.1269424373753606065436561036e+21,
0.1092152214043184787101134641e+19,
-0.5454629264396819144157448868e+16,
0.1634659487571284628830445048e+14,
-0.2909662785381647825756152444e+11,
0.2853433451054763915026471449e+08,
-0.1197705712815379389149134705e+05
};
static double q[10] = {
0.3842352615521596256098041912e+25,
0.3507567066272028105798868716e+23,
0.1611334311633414344007062889e+21,
0.4929612313959850319632645381e+18,
0.1117536965288162684489793105e+16,
0.1969278625584719037168592923e+13,
0.2735606122949877990248154504e+10,
0.2940957355049651347475558106e+07,
0.2274736606126590905134610965e+04,
0.1000000000000000000000000000e+01
};
double xsq = x*x;
return x * POLYNOM9(xsq, p) / POLYNOM9(xsq, q);
}
double
j1(x)
double x;
{
/* Use J1(x) = sqrt(2/(pi*x))*(P1(x)*cos(X1)-Q1(x)*sin(X1))
where X1 = x - 3*pi/4 for |x| > 8.
Use J1(-x) = -J1(x).
Use direct approximation of smallj1 for |x| <= 8.
*/
extern double sqrt(), sin(), cos();
int negative = x < 0.0;
if (negative) x = -x;
if (x > 8.0) {
double X1 = x - (M_PI - M_PI_4);
x = sqrt(M_2_PI/x)*(P1(x)*cos(X1) - Q1(x)*sin(X1));
}
else x = smallj1(x);
if (negative) return -x;
return x;
}
static double
smally1_bar(x)
double x;
{
/* Y1(x) = Y1BAR(x)+(2/pi)*(J1(x)ln(x) - 1/x)
Approximation of Y1BAR for 0 <= x <= 8:
Y1BAR(x) = x*P(x*x)/Q(x*x)
Hart & Cheney # 6449
*/
static double p[10] = {
-0.5862655424363443992938931700e+24,
0.1570668341992328458208364904e+24,
-0.7351681299005467428400402479e+22,
0.1390658785759080111485190942e+21,
-0.1339544201526785345938109179e+19,
0.7290257386242270629526344379e+16,
-0.2340575603057015935501295099e+14,
0.4411516199185230690878878903e+11,
-0.4542128738770213026987060358e+08,
0.1988612563465350530472715888e+05
};
static double q[10] = {
0.2990279721605116022908679994e+25,
0.2780285010357803058127175655e+23,
0.1302687474507355553192845146e+21,
0.4071330372239164349602952937e+18,
0.9446611865086570116528399283e+15,
0.1707657951197456205887347694e+13,
0.2440358986882941823431612517e+10,
0.2708852767034077697963790196e+07,
0.2174361138333330803617969305e+04,
0.1000000000000000000000000000e+01
};
double xsq = x*x;
return x * POLYNOM9(xsq, p) / POLYNOM9(xsq, q);
}
double
y1(x)
double x;
{
extern double sqrt(), sin(), cos(), log();
if (x <= 0.0) {
errno = EDOM;
return -HUGE;
}
if (x > 8.0) {
double X1 = x - (M_PI - M_PI_4);
return sqrt(M_2_PI/x) * (P1(x)*sin(X1)+Q1(x)*cos(X1));
}
return smally1_bar(x) + M_2_PI*(j1(x)*log(x) - 1/x);
}

121
lang/cem/libcc/math/jn.c Normal file
View file

@ -0,0 +1,121 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
double
yn(n, x)
double x;
{
/* Use y0, y1, and the recurrence relation
y(n+1,x) = 2*n*y(n,x)/x - y(n-1, x).
According to Hart & Cheney, this is stable for all
x, n.
Also use: y(-n,x) = (-1)^n * y(n, x)
*/
int negative = 0;
extern double y0(), y1();
double yn1, yn2;
register int i;
if (x <= 0) {
errno = EDOM;
return -HUGE;
}
if (n < 0) {
n = -n;
negative = (n % 2);
}
if (n == 0) return y0(x);
if (n == 1) return y1(x);
yn2 = y0(x);
yn1 = y1(x);
for (i = 1; i < n; i++) {
double tmp = yn1;
yn1 = (i*2)*yn1/x - yn2;
yn2 = tmp;
}
if (negative) return -yn1;
return yn1;
}
double
jn(n, x)
double x;
{
/* Unfortunately, according to Hart & Cheney, the recurrence
j(n+1,x) = 2*n*j(n,x)/x - j(n-1,x) is unstable for
increasing n, except when x > n.
However, j(n,x)/j(n-1,x) = 2/(2*n-x*x/(2*(n+1)-x*x/( ....
(a continued fraction).
We can use this to determine KJn and KJn-1, where K is a
normalization constant not yet known. This enables us
to determine KJn-2, ...., KJ1, KJ0. Now we can use the
J0 or J1 approximation to determine K.
Use: j(-n, x) = (-1)^n * j(n, x)
j(n, -x) = (-1)^n * j(n, x)
*/
extern double j0(), j1();
if (n < 0) {
n = -n;
x = -x;
}
if (n == 0) return j0(x);
if (n == 1) return j1(x);
if (x > n) {
/* in this case, the recurrence relation is stable for
increasing n, so we use that.
*/
double jn2 = j0(x), jn1 = j1(x);
register int i;
for (i = 1; i < n; i++) {
double tmp = jn1;
jn1 = (2*i)*jn1/x - jn2;
jn2 = tmp;
}
return jn1;
}
{
/* we first compute j(n,x)/j(n-1,x) */
register int i;
double quotient = 0.0;
double xsqr = x*x;
double jn1, jn2;
for (i = 20; /* ??? how many do we need ??? */
i > 0; i--) {
quotient = xsqr/(2*(i+n) - quotient);
}
quotient = x / (2*n - quotient);
jn1 = quotient;
jn2 = 1.0;
for (i = n-1; i > 0; i--) {
/* recurrence relation is stable for decreasing n
*/
double tmp = jn2;
jn2 = (2*i)*jn2/x - jn1;
jn1 = tmp;
}
/* So, now we have K*Jn = quotient and K*J0 = jn2.
Now it is easy; compute real j0, this gives K = jn2/j0,
and this then gives Jn = quotient/K = j0 * quotient / jn2.
*/
return j0(x)*quotient/jn2;
}
}

56
lang/cem/libcc/math/log.c Normal file
View file

@ -0,0 +1,56 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
extern int errno;
double
log(x)
double x;
{
/* log(x) = z*P(z*z)/Q(z*z), z = (x-1)/(x+1), x in [1/sqrt(2), sqrt(2)]
*/
/* Hart & Cheney #2707 */
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 frexp();
double z, zsqr;
int exponent;
if (x <= 0) {
errno = EDOM;
return 0;
}
x = frexp(x, &exponent);
while (x < M_1_SQRT2) {
x += x;
exponent--;
}
z = (x-1)/(x+1);
zsqr = z*z;
return z * POLYNOM4(zsqr, p) / POLYNOM4(zsqr, q) + exponent * M_LN2;
}

View file

@ -0,0 +1,27 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
extern int errno;
double
log10(x)
double x;
{
extern double log();
if (x <= 0) {
errno = EDOM;
return 0;
}
return log(x) / M_LN10;
}

40
lang/cem/libcc/math/pow.c Normal file
View file

@ -0,0 +1,40 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
extern int errno;
double
pow(x,y)
double x,y;
{
double dummy;
extern double modf(), exp(), log();
if ((x == 0 && y == 0) ||
(x < 0 && modf(y, &dummy) != 0)) {
errno = EDOM;
return 0;
}
if (x == 0) return x;
if (x < 0) {
double val = exp(log(-x) * y);
if (modf(y/2.0, &dummy) != 0) {
/* y was odd */
val = - val;
}
return val;
}
return exp(log(x) * y);
}

115
lang/cem/libcc/math/sin.c Normal file
View file

@ -0,0 +1,115 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
extern int errno;
static double
sinus(x, quadrant)
double x;
{
/* sin(0.5*pi*x) = x * P(x*x)/Q(x*x) for x in [0,1] */
/* Hart & Cheney # 3374 */
static double p[6] = {
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;
}
if (M_PI_2 - x == M_PI_2) {
switch(quadrant) {
case 0:
case 2:
return 0.0;
case 1:
return 1.0;
case 3:
return -1.0;
}
}
if (x >= M_2PI) {
if (x <= 0x7fffffff) {
/* Use extended precision to calculate reduced argument.
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 modf();
double dummy;
x = modf(x/M_2PI, &dummy) * M_2PI;
}
}
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
sin(x)
double x;
{
return sinus(x, 0);
}
double
cos(x)
double x;
{
if (x < 0) x = -x;
return sinus(x, 1);
}

View file

@ -0,0 +1,42 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
extern int errno;
double
sinh(x)
double x;
{
int negx = x < 0;
extern double exp();
if (negx) {
x = -x;
}
if (x > M_LN_MAX_D) {
/* exp(x) would overflow */
if (x >= M_LN_MAX_D + M_LN2) {
/* not representable */
x = HUGE;
errno = ERANGE;
}
else x = exp (x - M_LN2);
}
else {
double expx = exp(x);
x = 0.5 * (expx - 1.0/expx);
}
if (negx) {
return -x;
}
return x;
}

View file

@ -0,0 +1,41 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
extern int errno;
#define NITER 5
double
sqrt(x)
double x;
{
extern double frexp(), ldexp();
int exponent;
double val;
if (x <= 0) {
if (x < 0) errno = EDOM;
return 0;
}
val = frexp(x, &exponent);
if (exponent & 1) {
exponent--;
val *= 2;
}
val = ldexp(val + 1.0, exponent/2 - 1);
/* was: val = (val + 1.0)/2.0; val = ldexp(val, exponent/2); */
for (exponent = NITER - 1; exponent >= 0; exponent--) {
val = (val + x / val) / 2.0;
}
return val;
}

126
lang/cem/libcc/math/tan.c Normal file
View file

@ -0,0 +1,126 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
extern int errno;
double
tan(x)
double x;
{
/* First reduce range to [0, pi/4].
Then use approximation tan(x*pi/4) = x * P(x*x)/Q(x*x).
Hart & Cheney # 4288
Use: tan(x) = 1/tan(pi/2 - x)
tan(-x) = -tan(x)
tan(x+k*pi) = tan(x)
*/
static double p[5] = {
-0.5712939549476836914932149599e+10,
0.4946855977542506692946040594e+09,
-0.9429037070546336747758930844e+07,
0.5282725819868891894772108334e+05,
-0.6983913274721550913090621370e+02
};
static double q[6] = {
-0.7273940551075393257142652672e+10,
0.2125497341858248436051062591e+10,
-0.8000791217568674135274814656e+08,
0.8232855955751828560307269007e+06,
-0.2396576810261093558391373322e+04,
0.1000000000000000000000000000e+01
};
int negative = x < 0;
double tmp, tmp1, tmp2;
double xsq;
int invert = 0;
int ip;
if (negative) x = -x;
/* first reduce to [0, pi) */
if (x >= M_PI) {
if (x <= 0x7fffffff) {
/* Use extended precision to calculate reduced argument.
Split pi 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*pi as ((x1 - n*a1) + x2) - n*a2.
*/
#define A1 3.14111328125
#define A2 0.00047937233979323846264338327950288
double n = (long) (x / M_PI);
double x1 = (long) x;
double x2 = x - x1;
x = x1 - n * A1;
x += x2;
x -= n * A2;
#undef A1
#undef A2
}
else {
extern double modf();
x = modf(x/M_PI, &tmp) * M_PI;
}
}
/* because the approximation uses x*pi/4, we reverse this */
x /= M_PI_4;
ip = (int) x;
x -= ip;
switch(ip) {
case 0:
/* [0,pi/4] */
break;
case 1:
/* [pi/4, pi/2]
tan(x+pi/4) = 1/tan(pi/2 - (x+pi/4)) = 1/tan(pi/4 - x)
*/
invert = 1;
x = 1.0 - x;
break;
case 2:
/* [pi/2, 3pi/4]
tan(x+pi/2) = tan((x+pi/2)-pi) = -tan(pi/2 - x) =
-1/tan(x)
*/
negative = ! negative;
invert = 1;
break;
case 3:
/* [3pi/4, pi)
tan(x+3pi/4) = tan(x-pi/4) = - tan(pi/4-x)
*/
x = 1.0 - x;
negative = ! negative;
break;
}
xsq = x * x;
tmp1 = x*POLYNOM4(xsq, p);
tmp2 = POLYNOM5(xsq, q);
tmp = tmp1 / tmp2;
if (invert) {
if (tmp == 0.0) {
errno = ERANGE;
tmp = HUGE;
}
else tmp = tmp2 / tmp1;
}
return negative ? -tmp : tmp;
}

View file

@ -0,0 +1,27 @@
/*
* (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
*/
/* $Header$ */
#include <math.h>
#include <errno.h>
double
tanh(x)
double x;
{
extern double exp();
if (x <= 0.5*M_LN_MIN_D) {
return -1;
}
if (x >= 0.5*M_LN_MAX_D) {
return 1;
}
x = exp(x + x);
return (x - 1.0)/(x + 1.0);
}

193
lang/cem/libcc/math/test.c Normal file
View file

@ -0,0 +1,193 @@
/*
* (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
*/
#include <math.h>
#include <stdio.h>
#define EPS_D 5.0e-14
main()
{
testsqrt();
testtrig();
testexplog();
testgamma();
testbessel();
}
dotest(s, x, d, v)
char *s;
double x, d, v;
{
double fabs();
if (fabs((v - d) / (fabs(v) < EPS_D ? 1.0 : v)) > EPS_D) {
printf(s, x);
printf(" = %.16e, should be %.16e\n", d, v);
}
}
testsqrt()
{
#define SQRT2 M_SQRT2
#define SQRT10 3.16227766016837933199889354443271853
double x, val;
extern double sqrt();
dotest("sqrt(%.1f)", 2.0, sqrt(2.0), SQRT2);
dotest("sqrt(%.1f)", 10.0, sqrt(10.0), SQRT10);
for (x = 0.1; x < 0.1e20; x += x) {
val = sqrt(x);
dotest("sqrt(%.1f)^2", x, val*val, x);
}
}
testtrig()
{
#define SINPI_24 0.13052619222005159154840622789548901
#define SINPI_16 0.19509032201612826784828486847702224
#define SINPI_12 0.25881904510252076234889883762404832
#define SINPI_6 0.5
#define SINPI_4 M_1_SQRT2
#define SINPI_3 0.86602540378443864676372317075293618
#define SINPI_2 1.0
#define SIN0 0.0
double x;
extern double sin(), cos(), tan(), asin(), acos(), atan(), fabs();
dotest("sin(0)", 0.0, sin(0.0), SIN0);
dotest("sin(pi/24)", M_PI/24 , sin(M_PI/24), SINPI_24);
dotest("sin(pi/16)", M_PI/16 , sin(M_PI/16), SINPI_16);
dotest("sin(pi/12)", M_PI/12 , sin(M_PI/12), SINPI_12);
dotest("sin(pi/6)", M_PI/6 , sin(M_PI/6), SINPI_6);
dotest("sin(pi/4)", M_PI_4 , sin(M_PI_4), SINPI_4);
dotest("sin(pi/3)", M_PI/3 , sin(M_PI/3), SINPI_3);
dotest("sin(pi/2)", M_PI_2 , sin(M_PI_2), SINPI_2);
dotest("sin(pi)", 0.0, sin(M_PI), SIN0);
dotest("sin(3*pi/2)", 0.0, sin(M_PI+M_PI_2), -SINPI_2);
dotest("sin(-pi/24)", -M_PI/24 , sin(-M_PI/24), -SINPI_24);
dotest("sin(-pi/16)", -M_PI/16 , sin(-M_PI/16), -SINPI_16);
dotest("sin(-pi/12)", -M_PI/12 , sin(-M_PI/12), -SINPI_12);
dotest("sin(-pi/6)", -M_PI/6 , sin(-M_PI/6), -SINPI_6);
dotest("sin(-pi/4)", -M_PI_4 , sin(-M_PI_4), -SINPI_4);
dotest("sin(-pi/3)", -M_PI/3 , sin(-M_PI/3), -SINPI_3);
dotest("sin(-pi/2)", -M_PI_2 , sin(-M_PI_2), -SINPI_2);
dotest("cos(pi/2)", M_PI_2, cos(M_PI_2), SIN0);
dotest("cos(11pi/24)", M_PI/24 , cos(11*M_PI/24), SINPI_24);
dotest("cos(7pi/16)", M_PI/16 , cos(7*M_PI/16), SINPI_16);
dotest("cos(5pi/12)", M_PI/12 , cos(5*M_PI/12), SINPI_12);
dotest("cos(pi/3)", M_PI/6 , cos(M_PI/3), SINPI_6);
dotest("cos(pi/4)", M_PI_4 , cos(M_PI_4), SINPI_4);
dotest("cos(pi/6)", M_PI/3 , cos(M_PI/6), SINPI_3);
dotest("cos(0)", M_PI_2 , cos(0), SINPI_2);
dotest("cos(pi)", M_PI , cos(M_PI), -SINPI_2);
dotest("cos(3pi/2)", M_PI , cos(M_PI+M_PI_2), SIN0);
dotest("cos(-pi/2)", M_PI_2, cos(-M_PI_2), SIN0);
dotest("cos(-11pi/24)", M_PI/24 , cos(-11*M_PI/24), SINPI_24);
dotest("cos(-7pi/16)", M_PI/16 , cos(-7*M_PI/16), SINPI_16);
dotest("cos(-5pi/12)", M_PI/12 , cos(-5*M_PI/12), SINPI_12);
dotest("cos(-pi/3)", M_PI/6 , cos(-M_PI/3), SINPI_6);
dotest("cos(-pi/4)", M_PI_4 , cos(-M_PI_4), SINPI_4);
dotest("cos(-pi/6)", M_PI/3 , cos(-M_PI/6), SINPI_3);
for (x = -10; x <= 10; x += 0.5) {
dotest("sin+2*pi-sin(%.2f)", x, sin(x+M_2PI)-sin(x), 0.0);
dotest("cos+2*pi-cos(%.2f)", x, cos(x+M_2PI)-cos(x), 0.0);
dotest("tan+2*pi-tan(%.2f)", x, tan(x+M_2PI)-tan(x), 0.0);
dotest("tan+pi-tan(%.2f)", x, tan(x+M_PI)-tan(x), 0.0);
}
for (x = -1.5; x <= 1.5; x += 0.1) {
dotest("asin(sin(%.2f))", x, asin(sin(x)), x);
dotest("acos(cos(%.2f))", x, acos(cos(x)), fabs(x));
dotest("atan(tan(%.2f))", x, atan(tan(x)), x);
}
}
testexplog()
{
#define EXPMIN1 0.36787944117144232159552377016146087 /* exp(-1) */
#define EXPMIN1_4 0.77880078307140486824517026697832065 /* exp(-1/4) */
#define EXP0 1.0 /* exp(0) */
#define EXP1_4 1.28402541668774148407342056806243646 /* exp(1/4) */
#define EXP1 M_E /* exp(1) */
#define LN1 0.0 /* log(1) */
#define LN2 M_LN2 /* log(2) */
#define LN4 1.38629436111989061883446424291635313 /* log(4) */
#define LNE 1.0 /* log(e) */
#define LN10 M_LN10 /* log(10) */
extern double exp(), log();
double x;
dotest("exp(%.2f)", -1.0, exp(-1.0), EXPMIN1);
dotest("exp(%.2f)", -0.25, exp(-0.25), EXPMIN1_4);
dotest("exp(%.2f)", 0.0, exp(0.0), EXP0);
dotest("exp(%.2f)", 0.25, exp(0.25), EXP1_4);
dotest("exp(%.2f)", 1.0, exp(1.0), EXP1);
dotest("log(%.2f)", 1.0, log(1.0), LN1);
dotest("log(%.2f)", 2.0, log(2.0), LN2);
dotest("log(%.2f)", 4.0, log(4.0), LN4);
dotest("log(%.2f)", 10.0, log(10.0), LN10);
dotest("log(e)", M_E, log(M_E), LNE);
for (x = -30.0; x <= 30.0; x += 0.5) {
dotest("log(exp(%.2f))", x, log(exp(x)), x);
}
}
testgamma()
{
double x, xfac;
extern double gamma(), exp();
for (x = 1.0, xfac = 1.0; x < 30.0; x += 1.0) {
dotest("exp(gamma(%.2f))", x, exp(gamma(x)), xfac);
xfac *= x;
}
}
testbessel()
{
#define J0__PI_4 0.85163191370480801270040601506092607 /* j0(pi/4) */
#define J0__PI_2 0.47200121576823476744766838787250096 /* j0(pi/2) */
#define J1__PI_4 0.36318783834686733179559374778892472 /* j1(pi/4) */
#define J1__PI_2 0.56682408890587393771124496346716028 /* j1(pi/2) */
#define J10__PI_4 0.00000000002369974904082422018721148 /* j10(p1/4) */
#define J10__PI_2 0.00000002326614794865976450546482206 /* j10(pi/2) */
extern double j0(), j1(), jn(), yn();
register int n;
double x;
extern char *sprintf();
char buf[100];
dotest("j0(pi/4)", M_PI_4, j0(M_PI_4), J0__PI_4);
dotest("j0(pi/2)", M_PI_2, j0(M_PI_2), J0__PI_2);
dotest("j1(pi/4)", M_PI_4, j1(M_PI_4), J1__PI_4);
dotest("j1(pi/2)", M_PI_2, j1(M_PI_2), J1__PI_2);
dotest("j10(pi/4)", M_PI_4, jn(10,M_PI_4), J10__PI_4);
dotest("j10(pi/2)", M_PI_2, jn(10,M_PI_2), J10__PI_2);
/* Also check consistency using the Wronskian relation
jn(n+1,x)*yn(n, x) - jn(n,x)*yn(n+1,x) = 2/(pi*x)
*/
for (x = 0.1; x < 20.0; x += 0.5) {
double two_over_pix = M_2_PI/x;
for (n = 0; n <= 10; n++) {
dotest(sprintf(buf, "jn(%d,%.2f)*yn(%d,%.2f)-jn(%d,%.2f)*yn(%d,%.2f)",n+1,x,n,x,n,x,n+1,x), x, jn(n+1,x)*yn(n,x)-jn(n,x)*yn(n+1,x),M_2_PI/x);
}
}
}