TeX 1995 July/TeX CD-ROM July 1995 (Disc 1)(Walnut Creek)(1995).ISO/graphics/gnuplot/standard.c

C/C++ Source or Header | 1993-09-15 | 20KB | 987 lines

#ifndef lint
static char *RCSid = "$Id: standard.c%v 3.50 1993/07/09 05:35:24 woo Exp $";
#endif


/* GNUPLOT - standard.c */
/*
 * Copyright (C) 1986 - 1993   Thomas Williams, Colin Kelley
 *
 * Permission to use, copy, and distribute this software and its
 * documentation for any purpose with or without fee is hereby granted,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.
 *
 * Permission to modify the software is granted, but not the right to
 * distribute the modified code.  Modifications are to be distributed
 * as patches to released version.
 *
 * This software is provided "as is" without express or implied warranty.
 *
 *
 * AUTHORS
 *
 *   Original Software:
 *     Thomas Williams,  Colin Kelley.
 *
 *   Gnuplot 2.0 additions:
 *       Russell Lang, Dave Kotz, John Campbell.
 *
 *   Gnuplot 3.0 additions:
 *       Gershon Elber and many others.
 *
 */

#include <math.h>
#include <stdio.h>
#include "plot.h"

#ifdef vms
#include <errno.h>
#else
extern int errno;
#endif /* vms */


extern struct value stack[STACK_DEPTH];
extern int s_p;
extern double zero;

struct value *pop(), *Gcomplex(), *Ginteger();

double magnitude(), angle(), real(), imag();

/* The bessel function approximations here are from
 * "Computer Approximations"
 * by Hart, Cheney et al.
 * John Wiley & Sons, 1968
 */

/* There appears to be a mistake in Hart, Cheney et al. on page 149.
 * Where it list Qn(x)/x ~ P(z*z)/Q(z*z), z = 8/x, it should read
 *               Qn(x)/z ~ P(z*z)/Q(z*z), z = 8/x
 * In the functions below, Qn(x) is implementated using the later
 * equation.
 * These bessel functions are accurate to about 1e-13
 */

#if defined (ATARI) && defined(__PUREC__)
/* Sorry. But PUREC bugs here.
 * These bessel functions are NOT accurate to about 1e-13
 */

#define PI_ON_FOUR     0.785398163397448309615661
#define PI_ON_TWO     1.570796326794896619231313
#define THREE_PI_ON_FOUR 2.356194490192344928846982
#define TWO_ON_PI     0.636619772367581343075535

static double dzero = 0.0;

/* jzero for x in [0,8]
 * Index 5849, 19.22 digits precision
 */
static double pjzero[] = {
     0.493378725179413356181681e+21,
    -0.117915762910761053603844e+21,
     0.638205934107235656228943e+19,
    -0.136762035308817138686542e+18,
     0.143435493914034611166432e+16,
    -0.808522203485379387119947e+13,
     0.250715828553688194555516e+11,
    -0.405041237183313270636066e+8,
     0.268578685698001498141585e+5
};

static double qjzero[] = {
     0.493378725179413356211328e+21,
     0.542891838409228516020019e+19,
     0.302463561670946269862733e+17,
     0.112775673967979850705603e+15,
     0.312304311494121317257247e+12,
     0.669998767298223967181403e+9,
     0.111463609846298537818240e+7,
     0.136306365232897060444281e+4,
     0.1e+1
};

/* pzero for x in [8,inf]
 * Index 6548, 18.16 digits precision
 */
static double ppzero[] = {
     0.227790901973046843022700e+5,
     0.413453866395807657967802e+5,
     0.211705233808649443219340e+5,
     0.348064864432492703474453e+4,
     0.153762019090083542957717e+3,
     0.889615484242104552360748e+0
};

static double qpzero[] = {
     0.227790901973046843176842e+5,
     0.413704124955104166398920e+5,
     0.212153505618801157304226e+5,
     0.350287351382356082073561e+4,
     0.157111598580808936490685e+3,
     0.1e+1
};

/* qzero for x in [8,inf]
 * Index 6948, 18.33 digits precision
 */
static double pqzero[] = {
    -0.892266002008000940984692e+2,
    -0.185919536443429938002522e+3,
    -0.111834299204827376112621e+3,
    -0.223002616662141984716992e+2,
    -0.124410267458356384591379e+1,
    -0.8803330304868075181663e-2,
};

static double qqzero[] = {
     0.571050241285120619052476e+4,
     0.119511315434346136469526e+5,
     0.726427801692110188369134e+4,
     0.148872312322837565816135e+4,
     0.905937695949931258588188e+2,
     0.1e+1
};


/* yzero for x in [0,8]
 * Index 6245, 18.78 digits precision
 */
static double pyzero[] = {
    -0.275028667862910958370193e+20,
     0.658747327571955492599940e+20,
    -0.524706558111276494129735e+19,
     0.137562431639934407857134e+18,
    -0.164860581718572947312208e+16,
     0.102552085968639428450917e+14,
    -0.343637122297904037817103e+11,
     0.591521346568688965427383e+8,
    -0.413703549793314855412524e+5
};

static double qyzero[] = {
     0.372645883898616588198998e+21,
     0.419241704341083997390477e+19,
     0.239288304349978185743936e+17,
     0.916203803407518526248915e+14,
     0.261306575504108124956848e+12,
     0.579512264070072953738009e+9,
     0.100170264128890626566665e+7,
     0.128245277247899380417633e+4,
     0.1e+1
};


/* jone for x in [0,8]
 * Index 6050, 20.98 digits precision
 */
static double pjone[] = {
     0.581199354001606143928051e+21,
    -0.667210656892491629802094e+20,
     0.231643358063400229793182e+19,
    -0.358881756991010605074364e+17,
     0.290879526383477540973760e+15,
    -0.132298348033212645312547e+13,
     0.341323418230170053909129e+10,
    -0.469575353064299585976716e+7,
     0.270112271089232341485679e+4
};

static double qjone[] = {
     0.116239870800321228785853e+22,
     0.118577071219032099983711e+20,
     0.609206139891752174610520e+17,
     0.208166122130760735124018e+15,
     0.524371026216764971540673e+12,
     0.101386351435867398996705e+10,
     0.150179359499858550592110e+7,
     0.160693157348148780197092e+4,
     0.1e+1
};


/* pone for x in [8,inf]
 * Index 6749, 18.11 digits precision
 */
static double ppone[] = {
     0.352246649133679798341724e+5,
     0.627588452471612812690057e+5,
     0.313539631109159574238670e+5,
     0.498548320605943384345005e+4,
     0.211152918285396238210572e+3,
     0.12571716929145341558495e+1
};

static double qpone[] = {
     0.352246649133679798068390e+5,
     0.626943469593560511888834e+5,
     0.312404063819041039923016e+5,
     0.493039649018108897938610e+4,
     0.203077518913475932229357e+3,
     0.1e+1
};

/* qone for x in [8,inf]
 * Index 7149, 18.28 digits precision
 */
static double pqone[] = {
     0.351175191430355282253332e+3,
     0.721039180490447503928086e+3,
     0.425987301165444238988699e+3,
     0.831898957673850827325226e+2,
     0.45681716295512267064405e+1,
     0.3532840052740123642735e-1
};

static double qqone[] = {
     0.749173741718091277145195e+4,
     0.154141773392650970499848e+5,
     0.915223170151699227059047e+4,
     0.181118670055235135067242e+4,
     0.103818758546213372877664e+3,
     0.1e+1
};


/* yone for x in [0,8]
 * Index 6444, 18.24 digits precision
 */
static double pyone[] = {
    -0.292382196153296254310105e+20,
     0.774852068218683964508809e+19,
    -0.344104806308411444618546e+18,
     0.591516076049007061849632e+16,
    -0.486331694256717507482813e+14,
     0.204969667374566218261980e+12,
    -0.428947196885524880182182e+9,
     0.355692400983052605669132e+6
};

static double qyone[] = {
     0.149131151130292035017408e+21,
     0.181866284170613498688507e+19,
     0.113163938269888452690508e+17,
     0.475517358888813771309277e+14,
     0.150022169915670898716637e+12,
     0.371666079862193028559693e+9,
     0.726914730719888456980191e+6,
     0.107269614377892552332213e+4,
     0.1e+1
};

#else

#define PI_ON_FOUR       0.78539816339744830961566084581987572
#define PI_ON_TWO        1.57079632679489661923131269163975144
#define THREE_PI_ON_FOUR 2.35619449019234492884698253745962716
#define TWO_ON_PI        0.63661977236758134307553505349005744

static double dzero = 0.0;

/* jzero for x in [0,8]
 * Index 5849, 19.22 digits precision
 */
static double pjzero[] = {
     0.4933787251794133561816813446e+21,
    -0.11791576291076105360384408e+21,
     0.6382059341072356562289432465e+19,
    -0.1367620353088171386865416609e+18,
     0.1434354939140346111664316553e+16,
    -0.8085222034853793871199468171e+13,
     0.2507158285536881945555156435e+11,
    -0.4050412371833132706360663322e+8,
     0.2685786856980014981415848441e+5
};

static double qjzero[] = {
    0.4933787251794133562113278438e+21,
    0.5428918384092285160200195092e+19,
    0.3024635616709462698627330784e+17,
    0.1127756739679798507056031594e+15,
    0.3123043114941213172572469442e+12,
    0.669998767298223967181402866e+9,
    0.1114636098462985378182402543e+7,
    0.1363063652328970604442810507e+4,
    0.1e+1
};

/* pzero for x in [8,inf]
 * Index 6548, 18.16 digits precision
 */
static double ppzero[] = {
    0.2277909019730468430227002627e+5,
    0.4134538663958076579678016384e+5,
    0.2117052338086494432193395727e+5,
    0.348064864432492703474453111e+4,
    0.15376201909008354295771715e+3,
    0.889615484242104552360748e+0
};

static double qpzero[] = {
    0.2277909019730468431768423768e+5,
    0.4137041249551041663989198384e+5,
    0.2121535056188011573042256764e+5,
    0.350287351382356082073561423e+4,
    0.15711159858080893649068482e+3,
    0.1e+1
};

/* qzero for x in [8,inf]
 * Index 6948, 18.33 digits precision
 */
static double pqzero[] = {
    -0.8922660020080009409846916e+2,
    -0.18591953644342993800252169e+3,
    -0.11183429920482737611262123e+3,
    -0.2230026166621419847169915e+2,
    -0.124410267458356384591379e+1,
    -0.8803330304868075181663e-2,
};

static double qqzero[] = {
    0.571050241285120619052476459e+4,
    0.1195113154343461364695265329e+5,
    0.726427801692110188369134506e+4,
    0.148872312322837565816134698e+4,
    0.9059376959499312585881878e+2,
    0.1e+1
};


/* yzero for x in [0,8]
 * Index 6245, 18.78 digits precision
 */
static double pyzero[] = {
    -0.2750286678629109583701933175e+20,
     0.6587473275719554925999402049e+20,
    -0.5247065581112764941297350814e+19,
     0.1375624316399344078571335453e+18,
    -0.1648605817185729473122082537e+16,
     0.1025520859686394284509167421e+14,
    -0.3436371222979040378171030138e+11,
     0.5915213465686889654273830069e+8,
    -0.4137035497933148554125235152e+5
};

static double qyzero[] = {
    0.3726458838986165881989980739e+21,
    0.4192417043410839973904769661e+19,
    0.2392883043499781857439356652e+17,
    0.9162038034075185262489147968e+14,
    0.2613065755041081249568482092e+12,
    0.5795122640700729537380087915e+9,
    0.1001702641288906265666651753e+7,
    0.1282452772478993804176329391e+4,
    0.1e+1
};


/* jone for x in [0,8]
 * Index 6050, 20.98 digits precision
 */
static double pjone[] = {
     0.581199354001606143928050809e+21,
    -0.6672106568924916298020941484e+20,
     0.2316433580634002297931815435e+19,
    -0.3588817569910106050743641413e+17,
     0.2908795263834775409737601689e+15,
    -0.1322983480332126453125473247e+13,
     0.3413234182301700539091292655e+10,
    -0.4695753530642995859767162166e+7,
     0.270112271089232341485679099e+4
};

static double qjone[] = {
    0.11623987080032122878585294e+22,
    0.1185770712190320999837113348e+20,
    0.6092061398917521746105196863e+17,
    0.2081661221307607351240184229e+15,
    0.5243710262167649715406728642e+12,
    0.1013863514358673989967045588e+10,
    0.1501793594998585505921097578e+7,
    0.1606931573481487801970916749e+4,
    0.1e+1
};


/* pone for x in [8,inf]
 * Index 6749, 18.11 digits precision
 */
static double ppone[] = {
    0.352246649133679798341724373e+5,
    0.62758845247161281269005675e+5,
    0.313539631109159574238669888e+5,
    0.49854832060594338434500455e+4,
    0.2111529182853962382105718e+3,
    0.12571716929145341558495e+1
};

static double qpone[] = {
    0.352246649133679798068390431e+5,
    0.626943469593560511888833731e+5,
    0.312404063819041039923015703e+5,
    0.4930396490181088979386097e+4,
    0.2030775189134759322293574e+3,
    0.1e+1
};

/* qone for x in [8,inf]
 * Index 7149, 18.28 digits precision
 */
static double pqone[] = {
    0.3511751914303552822533318e+3,
    0.7210391804904475039280863e+3,
    0.4259873011654442389886993e+3,
    0.831898957673850827325226e+2,
    0.45681716295512267064405e+1,
    0.3532840052740123642735e-1
};

static double qqone[] = {
    0.74917374171809127714519505e+4,
    0.154141773392650970499848051e+5,
    0.91522317015169922705904727e+4,
    0.18111867005523513506724158e+4,
    0.1038187585462133728776636e+3,
    0.1e+1
};


/* yone for x in [0,8]
 * Index 6444, 18.24 digits precision
 */
static double pyone[] = {
    -0.2923821961532962543101048748e+20,
     0.7748520682186839645088094202e+19,
    -0.3441048063084114446185461344e+18,
     0.5915160760490070618496315281e+16,
    -0.4863316942567175074828129117e+14,
     0.2049696673745662182619800495e+12,
    -0.4289471968855248801821819588e+9,
     0.3556924009830526056691325215e+6
};

static double qyone[] = {
    0.1491311511302920350174081355e+21,
    0.1818662841706134986885065935e+19,
    0.113163938269888452690508283e+17,
    0.4755173588888137713092774006e+14,
    0.1500221699156708987166369115e+12,
    0.3716660798621930285596927703e+9,
    0.726914730719888456980191315e+6,
    0.10726961437789255233221267e+4,
    0.1e+1
};

#endif /* ATARI && __PUREC__ */

f_real()
{
struct value a;
    push( Gcomplex(&a,real(pop(&a)), 0.0) );
}

f_imag()
{
struct value a;
    push( Gcomplex(&a,imag(pop(&a)), 0.0) );
}

f_arg()
{
struct value a;
    push( Gcomplex(&a,angle(pop(&a)), 0.0) );
}

f_conjg()
{
struct value a;
    (void) pop(&a);
    push( Gcomplex(&a,real(&a),-imag(&a) ));
}

f_sin()
{
struct value a;
    (void) pop(&a);
    push( Gcomplex(&a,sin(real(&a))*cosh(imag(&a)), cos(real(&a))*sinh(imag(&a))) );
}

f_cos()
{
struct value a;
    (void) pop(&a);
    push( Gcomplex(&a,cos(real(&a))*cosh(imag(&a)), -sin(real(&a))*sinh(imag(&a))));
}

f_tan()
{
struct value a;
register double den;
    (void) pop(&a);
    if (imag(&a) == 0.0)
        push( Gcomplex(&a,tan(real(&a)),0.0) );
    else {
        den = cos(2*real(&a))+cosh(2*imag(&a));
        if (den == 0.0) {
            undefined = TRUE;
            push( &a );
        }
        else
            push( Gcomplex(&a,sin(2*real(&a))/den, sinh(2*imag(&a))/den) );
    }
}

f_asin()
{
struct value a;
register double alpha, beta, x, y;
    (void) pop(&a);
    x = real(&a); y = imag(&a);
    if (y == 0.0) {
        if (fabs(x) > 1.0) {
            undefined = TRUE;
            push(Gcomplex(&a,0.0, 0.0));
        } else
            push( Gcomplex(&a,asin(x),0.0) );
    } else {
        beta  = sqrt((x + 1)*(x + 1) + y*y)/2 - sqrt((x - 1)*(x - 1) + y*y)/2;
        alpha = sqrt((x + 1)*(x + 1) + y*y)/2 + sqrt((x - 1)*(x - 1) + y*y)/2;
        push( Gcomplex(&a,asin(beta), log(alpha + sqrt(alpha*alpha-1))) );
    }
}

f_acos()
{
struct value a;
register double alpha, beta, x, y;
    (void) pop(&a);
    x = real(&a); y = imag(&a);
    if (y == 0.0) {
        if (fabs(x) > 1.0) {
            undefined = TRUE;
            push(Gcomplex(&a,0.0, 0.0));
        } else
            push( Gcomplex(&a,acos(x),0.0) );
    } else {
        alpha = sqrt((x + 1)*(x + 1) + y*y)/2 + sqrt((x - 1)*(x - 1) + y*y)/2;
        beta  = sqrt((x + 1)*(x + 1) + y*y)/2 - sqrt((x - 1)*(x - 1) + y*y)/2;
        push( Gcomplex(&a,acos(beta), log(alpha + sqrt(alpha*alpha-1))) );
    }
}

f_atan()
{
struct value a;
register double x, y, u, v, w, z;
    (void) pop(&a);
    x = real(&a); y = imag(&a);
    if (y == 0.0)
        push( Gcomplex(&a,atan(x), 0.0) );
    else if (x == 0.0 && fabs(y) == 1.0) {
        undefined = TRUE;
        push(Gcomplex(&a,0.0, 0.0));
    } else {
            if (x >= 0) {
                u = x;
            v = y;
        } else {
                u = -x;
            v = -y;
        }

            z = atan(2*u/(1-u*u-v*v));
        w = log((u*u+(v+1)*(v+1))/(u*u+(v-1)*(v-1)))/4;
        if (z < 0)
                z = z + 2*PI_ON_TWO;
        if (x < 0) {
                z = -z;
            w = -w;
        }
        push( Gcomplex(&a,0.5*z, w) );
    }
}

f_sinh()
{
struct value a;
    (void) pop(&a);
    push( Gcomplex(&a,sinh(real(&a))*cos(imag(&a)), cosh(real(&a))*sin(imag(&a))) );
}

f_cosh()
{
struct value a;
    (void) pop(&a);
    push( Gcomplex(&a,cosh(real(&a))*cos(imag(&a)), sinh(real(&a))*sin(imag(&a))) );
}

f_tanh()
{
struct value a;
register double den;
    (void) pop(&a);
    den = cosh(2*real(&a)) + cos(2*imag(&a));
    push( Gcomplex(&a,sinh(2*real(&a))/den, sin(2*imag(&a))/den) );
}

f_int()
{
struct value a;
    push( Ginteger(&a,(int)real(pop(&a))) );
}


f_abs()
{
struct value a;
    (void) pop(&a);
    switch (a.type) {
        case INTGR:
            push( Ginteger(&a,abs(a.v.int_val)) );
            break;
        case CMPLX:
            push( Gcomplex(&a,magnitude(&a), 0.0) );
    }
}

f_sgn()
{
struct value a;
    (void) pop(&a);
    switch(a.type) {
        case INTGR:
            push( Ginteger(&a,(a.v.int_val > 0) ? 1 :
                    (a.v.int_val < 0) ? -1 : 0) );
            break;
        case CMPLX:
            push( Ginteger(&a,(a.v.cmplx_val.real > 0.0) ? 1 :
                    (a.v.cmplx_val.real < 0.0) ? -1 : 0) );
            break;
    }
}


f_sqrt()
{
struct value a;
register double mag, ang;
    (void) pop(&a);
    mag = sqrt(magnitude(&a));
    if (imag(&a) == 0.0 && real(&a) < 0.0)
        push( Gcomplex(&a,0.0,mag) );
    else
    {
        if ( (ang = angle(&a)) < 0.0)
            ang += 2*Pi;
        ang /= 2;
        push( Gcomplex(&a,mag*cos(ang), mag*sin(ang)) );
    }
}


f_exp()
{
struct value a;
register double mag, ang;
    (void) pop(&a);
    mag = exp(real(&a));
    ang = imag(&a);
    push( Gcomplex(&a,mag*cos(ang), mag*sin(ang)) );
}


f_log10()
{
struct value a;
register double l10;;
    (void) pop(&a);
    l10 = log(10.0);    /***** replace with a constant! ******/
    push( Gcomplex(&a,log(magnitude(&a))/l10, angle(&a)/l10) );
}


f_log()
{
struct value a;
    (void) pop(&a);
    push( Gcomplex(&a,log(magnitude(&a)), angle(&a)) );
}


f_floor()
{
struct value a;

    (void) pop(&a);
    switch (a.type) {
        case INTGR:
            push( Ginteger(&a,(int)floor((double)a.v.int_val)));
            break;
        case CMPLX:
            push( Ginteger(&a,(int)floor(a.v.cmplx_val.real)));
    }
}


f_ceil()
{
struct value a;

    (void) pop(&a);
    switch (a.type) {
        case INTGR:
            push( Ginteger(&a,(int)ceil((double)a.v.int_val)));
            break;
        case CMPLX:
            push( Ginteger(&a,(int)ceil(a.v.cmplx_val.real)));
    }
}

/* bessel function approximations */
double jzero(x)
double x;
{
double p, q, x2;
int n;

    x2 = x * x;
    p = pjzero[8];
    q = qjzero[8];
    for (n=7; n>=0; n--) {
        p = p*x2 + pjzero[n];
        q = q*x2 + qjzero[n];
    }
    return(p/q);
}

double pzero(x)
double x;
{
double p, q, z, z2;
int n;

    z = 8.0 / x;
    z2 = z * z;
    p = ppzero[5];
    q = qpzero[5];
    for (n=4; n>=0; n--) {
        p = p*z2 + ppzero[n];
        q = q*z2 + qpzero[n];
    }
    return(p/q);
}

double qzero(x)
double x;
{
double p, q, z, z2;
int n;

    z = 8.0 / x;
    z2 = z * z;
    p = pqzero[5];
    q = qqzero[5];
    for (n=4; n>=0; n--) {
        p = p*z2 + pqzero[n];
        q = q*z2 + qqzero[n];
    }
    return(p/q);
}

double yzero(x)
double x;
{
double p, q, x2;
int n;

    x2 = x * x;
    p = pyzero[8];
    q = qyzero[8];
    for (n=7; n>=0; n--) {
        p = p*x2 + pyzero[n];
        q = q*x2 + qyzero[n];
    }
    return(p/q);
}

double rj0(x)
double x;
{
    if ( x <= 0.0 )
        x = -x;
    if ( x < 8.0 )
        return(jzero(x));
    else
        return( sqrt(TWO_ON_PI/x) *
            (pzero(x)*cos(x-PI_ON_FOUR) - 8.0/x*qzero(x)*sin(x-PI_ON_FOUR)) );

}

double ry0(x)
double x;
{
    if ( x < 0.0 )
        return(dzero/dzero); /* error */
    if ( x < 8.0 )
        return( yzero(x) + TWO_ON_PI*rj0(x)*log(x) );
    else
        return( sqrt(TWO_ON_PI/x) *
            (pzero(x)*sin(x-PI_ON_FOUR) +
            (8.0/x)*qzero(x)*cos(x-PI_ON_FOUR)) );

}


double jone(x)
double x;
{
double p, q, x2;
int n;

    x2 = x * x;
    p = pjone[8];
    q = qjone[8];
    for (n=7; n>=0; n--) {
        p = p*x2 + pjone[n];
        q = q*x2 + qjone[n];
    }
    return(p/q);
}

double pone(x)
double x;
{
double p, q, z, z2;
int n;

    z = 8.0 / x;
    z2 = z * z;
    p = ppone[5];
    q = qpone[5];
    for (n=4; n>=0; n--) {
        p = p*z2 + ppone[n];
        q = q*z2 + qpone[n];
    }
    return(p/q);
}

double qone(x)
double x;
{
double p, q, z, z2;
int n;

    z = 8.0 / x;
    z2 = z * z;
    p = pqone[5];
    q = qqone[5];
    for (n=4; n>=0; n--) {
        p = p*z2 + pqone[n];
        q = q*z2 + qqone[n];
    }
    return(p/q);
}

double yone(x)
double x;
{
double p, q, x2;
int n;

    x2 = x * x;
    p = 0.0;
    q = qyone[8];
    for (n=7; n>=0; n--) {
        p = p*x2 + pyone[n];
        q = q*x2 + qyone[n];
    }
    return(p/q);
}

double rj1(x)
double x;
{
double v,w;
    v = x;
    if ( x < 0.0 )
        x = -x;
    if ( x < 8.0 )
        return(v*jone(x));
    else {
        w = sqrt(TWO_ON_PI/x) *
            (pone(x)*cos(x-THREE_PI_ON_FOUR) -
               8.0/x*qone(x)*sin(x-THREE_PI_ON_FOUR)) ;
        if (v < 0.0)
            w = -w;
        return( w );
    }
}

double ry1(x)
double x;
{
    if ( x <= 0.0 )
        return(dzero/dzero); /* error */
    if ( x < 8.0 )
        return( x*yone(x) + TWO_ON_PI*(rj1(x)*log(x) - 1.0/x) );
    else
        return( sqrt(TWO_ON_PI/x) *
            (pone(x)*sin(x-THREE_PI_ON_FOUR) +
            (8.0/x)*qone(x)*cos(x-THREE_PI_ON_FOUR)) );
}


f_besj0()
{
struct value a;
    (void) pop(&a);
    if (fabs(imag(&a)) > zero)
        int_error("can only do bessel functions of reals",NO_CARET);
    push( Gcomplex(&a,rj0(real(&a)),0.0) );
}


f_besj1()
{
struct value a;
    (void) pop(&a);
    if (fabs(imag(&a)) > zero)
        int_error("can only do bessel functions of reals",NO_CARET);
    push( Gcomplex(&a,rj1(real(&a)),0.0) );
}


f_besy0()
{
struct value a;
    (void) pop(&a);
    if (fabs(imag(&a)) > zero)
        int_error("can only do bessel functions of reals",NO_CARET);
    if (real(&a) > 0.0)
        push( Gcomplex(&a,ry0(real(&a)),0.0) );
    else {
        push( Gcomplex(&a,0.0,0.0) );
        undefined = TRUE ;
    }
}


f_besy1()
{
struct value a;
    (void) pop(&a);
    if (fabs(imag(&a)) > zero)
        int_error("can only do bessel functions of reals",NO_CARET);
    if (real(&a) > 0.0)
        push( Gcomplex(&a,ry1(real(&a)),0.0) );
    else {
        push( Gcomplex(&a,0.0,0.0) );
        undefined = TRUE ;
    }
}