src/common/calfunc.c

#ifndef lint
static const char       RCSid[] = "$Id: calfunc.c,v 2.31 2024/02/26 20:55:00 greg Exp $";
#endif
/*
 *  calfunc.c - routines for calcomp using functions.
 *
 *      If VARIABLE is not set, only library functions
 *  can be accessed.
 *
 *  2/19/03     Eliminated conditional compiles in favor of esupport extern.
 */

#include "copyright.h"

#include  <stdio.h>
#include  <string.h>
#include  <errno.h>
#include  <stdlib.h>
#include  <math.h>

#include  "rterror.h"
#include  "calcomp.h"

                                /* bits in argument flag (better be right!) */
#define  AFLAGSIZ       (8*sizeof(unsigned long))
#define  ALISTSIZ       10      /* maximum saved argument list */

typedef struct activation {
    char  *name;                /* function name */
    struct activation  *prev;   /* previous activation */
    double  *ap;                /* argument list */
    unsigned long  an;          /* computed argument flags */
    EPNODE  *fun;               /* argument function */
}  ACTIVATION;          /* an activation record */

static ACTIVATION  *curact = NULL;

static double  libfunc(char *fname, VARDEF *vp);

#ifndef  MAXLIB
#define  MAXLIB         64      /* maximum number of library functions */
#endif

static double  l_if(char *), l_select(char *);
static double  l_min(char *), l_max(char *);
static double  l_rand(char *);
static double  l_floor(char *), l_ceil(char *);
static double  l_sqrt(char *);
static double  l_sin(char *), l_cos(char *), l_tan(char *);
static double  l_asin(char *), l_acos(char *), l_atan(char *), l_atan2(char *);
static double  l_exp(char *), l_log(char *), l_log10(char *);

                        /* functions must be listed alphabetically */
static ELIBR  library[MAXLIB] = {
    { "acos", 1, ':', l_acos },
    { "asin", 1, ':', l_asin },
    { "atan", 1, ':', l_atan },
    { "atan2", 2, ':', l_atan2 },
    { "ceil", 1, ':', l_ceil },
    { "cos", 1, ':', l_cos },
    { "exp", 1, ':', l_exp },
    { "floor", 1, ':', l_floor },
    { "if", 3, ':', l_if },
    { "log", 1, ':', l_log },
    { "log10", 1, ':', l_log10 },
    { "max", 1, ':', l_max },
    { "min", 1, ':', l_min },
    { "rand", 1, ':', l_rand },
    { "select", 1, ':', l_select },
    { "sin", 1, ':', l_sin },
    { "sqrt", 1, ':', l_sqrt },
    { "tan", 1, ':', l_tan },
};

static int  libsize = 18;

#define  resolve(ep)    ((ep)->type==VAR?(ep)->v.ln:eargf((ep)->v.chan))


int
fundefined(                     /* return # of req'd arguments for function */
        char  *fname
)
{
    ELIBR  *lp;
    VARDEF  *vp;

    if ((vp = varlookup(fname)) != NULL && vp->def != NULL
                && vp->def->v.kid->type == FUNC)
        return(nekids(vp->def->v.kid) - 1);
    lp = vp != NULL ? vp->lib : eliblookup(fname);
    if (lp == NULL)
        return(0);
    return(lp->nargs);
}


double
funvalue(                       /* return a function value to the user */
        char  *fname,
        int  n,
        double  *a
)
{
    ACTIVATION  act;
    VARDEF  *vp;
    double  rval;
                                        /* push environment */
    act.name = fname;
    act.prev = curact;
    act.ap = a;
    if (n < AFLAGSIZ)
        act.an = (1L<<n)-1;
    else {
        act.an = ~0;
        if (n > AFLAGSIZ)
            wputs("Excess arguments in funvalue()\n");
    }
    act.fun = NULL;
    curact = &act;

    if ((vp = varlookup(fname)) == NULL || vp->def == NULL
                || vp->def->v.kid->type != FUNC)
        rval = libfunc(fname, vp);
    else
        rval = evalue(vp->def->v.kid->sibling);

    curact = act.prev;                  /* pop environment */
    return(rval);
}


void
funset(                         /* set a library function */
        char  *fname,
        int  nargs,
        int  assign,
        double  (*fptr)(char *)
)
{
    int  oldlibsize = libsize;
    char *cp;
    ELIBR  *lp;
                                                /* check for context */
    for (cp = fname; *cp; cp++)
        ;
    if (cp == fname)
        return;
    while (cp[-1] == CNTXMARK) {
        *--cp = '\0';
        if (cp == fname) return;
    }
    if ((lp = eliblookup(fname)) == NULL) {     /* insert */
        if (fptr == NULL)
                return;                         /* nothing! */
        if (libsize >= MAXLIB) {
            eputs("Too many library functons!\n");
            quit(1);
        }
        for (lp = &library[libsize]; lp > library; lp--)
            if (strcmp(lp[-1].fname, fname) > 0)
                lp[0] = lp[-1];
            else
                break;
        libsize++;
    }
    if (fptr == NULL) {                         /* delete */
        while (lp < &library[libsize-1]) {
            lp[0] = lp[1];
            lp++;
        }
        libsize--;
    } else {                                    /* or assign */
        lp[0].fname = fname;            /* string must be static! */
        lp[0].nargs = nargs;
        lp[0].atyp = assign;
        lp[0].f = fptr;
    }
    if (libsize != oldlibsize)
        elibupdate(fname);                      /* relink library */
}


int
nargum(void)                    /* return number of available arguments */
{
    int  n;

    if (curact == NULL)
        return(0);
    if (curact->fun == NULL) {
        for (n = 0; (1L<<n) & curact->an; n++)
            ;
        return(n);
    }
    return(nekids(curact->fun) - 1);
}


double
argument(int n)                 /* return nth argument for active function */
{
    ACTIVATION  *actp = curact;
    EPNODE  *ep;
    double  aval;

    if (!actp | (--n < 0)) {
        eputs("Bad call to argument!\n");
        quit(1);
    }
    if ((n < AFLAGSIZ) & actp->an >> n)         /* already computed? */
        return(actp->ap[n]);

    if (!actp->fun || !(ep = ekid(actp->fun, n+1))) {
        eputs(actp->name);
        eputs(": too few arguments\n");
        quit(1);
    }
    curact = actp->prev;                        /* previous context */
    aval = evalue(ep);                          /* compute argument */
    curact = actp;                              /* put back calling context */
    if (n < ALISTSIZ) {                         /* save value if room */
        actp->ap[n] = aval;
        actp->an |= 1L<<n;
    }
    return(aval);
}


VARDEF *
eargf(int n)                    /* return function def for nth argument */
{
    ACTIVATION  *actp;
    EPNODE  *ep;

    for (actp = curact; actp != NULL; actp = actp->prev) {

        if (n <= 0)
            break;

        if (actp->fun == NULL)
            goto badarg;

        if ((ep = ekid(actp->fun, n)) == NULL) {
            eputs(actp->name);
            eputs(": too few arguments\n");
            quit(1);
        }
        if (ep->type == VAR)
            return(ep->v.ln);                   /* found it */

        if (ep->type != ARG)
            goto badarg;

        n = ep->v.chan;                         /* try previous context */
    }
    eputs("Bad call to eargf!\n");
    quit(1);

badarg:
    eputs(actp->name);
    eputs(": argument not a function\n");
    quit(1);
        return NULL; /* pro forma return */
}


char *
eargfun(int n)                  /* return function name for nth argument */
{
    return(eargf(n)->name);
}


double
efunc(EPNODE *ep)                       /* evaluate a function */
{
    ACTIVATION  act;
    double  alist[ALISTSIZ];
    double  rval;
    VARDEF  *dp;
                                        /* push environment */
    dp = resolve(ep->v.kid);
    act.name = dp->name;
    act.prev = curact;
    act.ap = alist;
    act.an = 0;
    act.fun = ep;
    curact = &act;

    if (dp->def == NULL || dp->def->v.kid->type != FUNC)
        rval = libfunc(act.name, dp);
    else
        rval = evalue(dp->def->v.kid->sibling);
    
    curact = act.prev;                  /* pop environment */
    return(rval);
}


double
eargument(                              /* evaluate an argument */
    EPNODE      *ep
)
{
    if ((ep->v.chan <= AFLAGSIZ) & curact->an >> (ep->v.chan-1))
        return(curact->ap[ep->v.chan-1]);

    return(argument(ep->v.chan));
}


ELIBR *
eliblookup(char *fname)         /* look up a library function */
{
    int  upper, lower;
    int  cm, i;

    lower = 0;
    upper = cm = libsize;

    while ((i = (lower + upper) >> 1) != cm) {
        cm = strcmp(fname, library[i].fname);
        if (cm > 0)
            lower = i;
        else if (cm < 0)
            upper = i;
        else
            return(&library[i]);
        cm = i;
    }
    return(NULL);
}


/*
 *  The following routines are for internal use:
 */


static double
libfunc(                                /* execute library function */
        char  *fname,
        VARDEF  *vp
)
{
    ELIBR  *lp;
    double  d;
    int  lasterrno;

    if (vp != NULL)
        lp = vp->lib;
    else
        lp = eliblookup(fname);
    if (lp == NULL) {
        eputs(fname);
        eputs(": undefined function\n");
        quit(1);
    }
    lasterrno = errno;
    errno = 0;
    d = (*lp->f)(lp->fname);
#ifdef  isnan
    if (errno == 0) {
        if (isnan(d))
            errno = EDOM;
        else if (isinf(d))
            errno = ERANGE;
    }
#endif
    if ((errno == EDOM) | (errno == ERANGE)) {
        wputs(fname);
        if (errno == EDOM)
                wputs(": domain error\n");
        else if (errno == ERANGE)
                wputs(": range error\n");
        else
                wputs(": error in call\n");
        return(0.0);
    }
    errno = lasterrno;
    return(d);
}


/*
 *  Library functions:
 */


static double
l_if(char *nm)          /* if(cond, then, else) conditional expression */
                        /* cond evaluates true if greater than zero */
{
    if (argument(1) > 0.0)
        return(argument(2));
    else
        return(argument(3));
}


static double
l_select(char *nm)      /* return argument #(A1+1) */
{
        int     narg = nargum();
        double  a1 = argument(1);
        int  n = (int)(a1 + .5);

        if ((a1 < -.5) | (n >= narg)) {
                errno = EDOM;
                return(0.0);
        }
        if (!n)         /* asking max index? */
                return(narg-1);
        return(argument(n+1));
}


static double
l_max(char *nm)         /* general maximum function */
{
        int  n = nargum();
        double  vmax = argument(1);

        while (n > 1) {
                double  v = argument(n--);
                if (vmax < v)
                        vmax = v;
        }
        return(vmax);
}


static double
l_min(char *nm)         /* general minimum function */
{
        int  n = nargum();
        double  vmin = argument(1);

        while (n > 1) {
                double  v = argument(n--);
                if (vmin > v)
                        vmin = v;
        }
        return(vmin);
}


static double
l_rand(char *nm)                /* random function between 0 and 1 */
{
    double  x;

    x = argument(1);
    x *= 1.0/(1.0 + x*x) + 2.71828182845904;
    x += .785398163397447 - floor(x);
    x = 1e5 / x;
    return(x - floor(x));
}


static double
l_floor(char *nm)               /* return largest integer not greater than arg1 */
{
    return(floor(argument(1)));
}


static double
l_ceil(char *nm)                /* return smallest integer not less than arg1 */
{
    return(ceil(argument(1)));
}


static double
l_sqrt(char *nm)
{
    return(sqrt(argument(1)));
}


static double
l_sin(char *nm)
{
    return(sin(argument(1)));
}


static double
l_cos(char *nm)
{
    return(cos(argument(1)));
}


static double
l_tan(char *nm)
{
    return(tan(argument(1)));
}


static double
l_asin(char *nm)
{
    return(asin(argument(1)));
}


static double
l_acos(char *nm)
{
    return(acos(argument(1)));
}


static double
l_atan(char *nm)
{
    return(atan(argument(1)));
}


static double
l_atan2(char *nm)
{
    return(atan2(argument(1), argument(2)));
}


static double
l_exp(char *nm)
{
    return(exp(argument(1)));
}


static double
l_log(char *nm)
{
    return(log(argument(1)));
}


static double
l_log10(char *nm)
{
    return(log10(argument(1)));
}
Revision:	2.32
Committed:	Mon Sep 16 17:31:14 2024 UTC (13 months, 2 weeks ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad6R0
Changes since 2.31:	+16 -16 lines
Log Message:	refactor: Changed too-generic symbol names in calcomp.h
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.32	static const char RCSid[] = "$Id: calfunc.c,v 2.31 2024/02/26 20:55:00 greg Exp $";
3	greg	1.1	#endif
4			/*
5			* calfunc.c - routines for calcomp using functions.
6			*
7	greg	2.8	* If VARIABLE is not set, only library functions
8			* can be accessed.
9			*
10			* 2/19/03 Eliminated conditional compiles in favor of esupport extern.
11			*/
12
13	greg	2.9	#include "copyright.h"
14	greg	1.1
15			#include <stdio.h>
16	schorsch	2.11	#include <string.h>
17	greg	1.1	#include <errno.h>
18	greg	2.30	#include <stdlib.h>
19	greg	2.5	#include <math.h>
20
21	schorsch	2.12	#include "rterror.h"
22	greg	1.1	#include "calcomp.h"
23
24	greg	1.5	/* bits in argument flag (better be right!) */
25			#define AFLAGSIZ (8*sizeof(unsigned long))
26	greg	2.29	#define ALISTSIZ 10 /* maximum saved argument list */
27	greg	1.1
28			typedef struct activation {
29			char name; / function name */
30			struct activation prev; / previous activation */
31			double ap; / argument list */
32			unsigned long an; /* computed argument flags */
33			EPNODE fun; / argument function */
34			} ACTIVATION; /* an activation record */
35
36			static ACTIVATION *curact = NULL;
37
38	schorsch	2.12	static double libfunc(char fname, VARDEF vp);
39	greg	1.1
40	greg	2.8	#ifndef MAXLIB
41	greg	1.1	#define MAXLIB 64 /* maximum number of library functions */
42	greg	2.8	#endif
43	greg	1.1
44	greg	2.21	static double l_if(char ), l_select(char );
45			static double l_min(char ), l_max(char );
46			static double l_rand(char *);
47	greg	2.13	static double l_floor(char ), l_ceil(char );
48			static double l_sqrt(char *);
49			static double l_sin(char ), l_cos(char ), l_tan(char *);
50			static double l_asin(char ), l_acos(char ), l_atan(char ), l_atan2(char );
51			static double l_exp(char ), l_log(char ), l_log10(char *);
52	greg	1.1
53			/* functions must be listed alphabetically */
54	greg	2.32	static ELIBR library[MAXLIB] = {
55	greg	1.4	{ "acos", 1, ':', l_acos },
56			{ "asin", 1, ':', l_asin },
57			{ "atan", 1, ':', l_atan },
58			{ "atan2", 2, ':', l_atan2 },
59			{ "ceil", 1, ':', l_ceil },
60			{ "cos", 1, ':', l_cos },
61			{ "exp", 1, ':', l_exp },
62			{ "floor", 1, ':', l_floor },
63			{ "if", 3, ':', l_if },
64			{ "log", 1, ':', l_log },
65			{ "log10", 1, ':', l_log10 },
66	greg	2.21	{ "max", 1, ':', l_max },
67			{ "min", 1, ':', l_min },
68	greg	1.4	{ "rand", 1, ':', l_rand },
69			{ "select", 1, ':', l_select },
70			{ "sin", 1, ':', l_sin },
71			{ "sqrt", 1, ':', l_sqrt },
72			{ "tan", 1, ':', l_tan },
73	greg	1.1	};
74
75	greg	2.22	static int libsize = 18;
76	greg	1.1
77	greg	2.32	#define resolve(ep) ((ep)->type==VAR?(ep)->v.ln:eargf((ep)->v.chan))
78	greg	1.1
79
80			int
81	greg	2.21	fundefined( /* return # of req'd arguments for function */
82	greg	2.16	char *fname
83			)
84	greg	1.1	{
85	greg	2.32	ELIBR *lp;
86	greg	2.16	VARDEF *vp;
87	greg	1.1
88	greg	2.7	if ((vp = varlookup(fname)) != NULL && vp->def != NULL
89			&& vp->def->v.kid->type == FUNC)
90	greg	1.1	return(nekids(vp->def->v.kid) - 1);
91	greg	2.32	lp = vp != NULL ? vp->lib : eliblookup(fname);
92	greg	2.7	if (lp == NULL)
93			return(0);
94			return(lp->nargs);
95	greg	1.1	}
96
97
98			double
99	greg	2.16	funvalue( /* return a function value to the user */
100			char *fname,
101			int n,
102			double *a
103			)
104	greg	1.1	{
105			ACTIVATION act;
106	greg	2.16	VARDEF *vp;
107	greg	1.1	double rval;
108			/* push environment */
109			act.name = fname;
110			act.prev = curact;
111			act.ap = a;
112	greg	2.19	if (n < AFLAGSIZ)
113			act.an = (1L<<n)-1;
114			else {
115	greg	1.5	act.an = ~0;
116	greg	2.19	if (n > AFLAGSIZ)
117			wputs("Excess arguments in funvalue()\n");
118			}
119	greg	1.1	act.fun = NULL;
120			curact = &act;
121
122			if ((vp = varlookup(fname)) == NULL \|\| vp->def == NULL
123			\|\| vp->def->v.kid->type != FUNC)
124			rval = libfunc(fname, vp);
125			else
126			rval = evalue(vp->def->v.kid->sibling);
127
128			curact = act.prev; /* pop environment */
129			return(rval);
130			}
131
132
133	greg	2.8	void
134	greg	2.16	funset( /* set a library function */
135			char *fname,
136			int nargs,
137			int assign,
138			double (fptr)(char )
139			)
140	greg	1.1	{
141	greg	2.6	int oldlibsize = libsize;
142	greg	2.8	char *cp;
143	greg	2.32	ELIBR *lp;
144	greg	2.8	/* check for context */
145			for (cp = fname; *cp; cp++)
146			;
147			if (cp == fname)
148			return;
149	greg	2.21	while (cp[-1] == CNTXMARK) {
150	greg	2.8	*--cp = '\0';
151	greg	2.21	if (cp == fname) return;
152			}
153	greg	2.32	if ((lp = eliblookup(fname)) == NULL) { /* insert */
154	greg	2.25	if (fptr == NULL)
155			return; /* nothing! */
156	greg	1.1	if (libsize >= MAXLIB) {
157			eputs("Too many library functons!\n");
158			quit(1);
159			}
160			for (lp = &library[libsize]; lp > library; lp--)
161	greg	2.17	if (strcmp(lp[-1].fname, fname) > 0)
162			lp[0] = lp[-1];
163			else
164	greg	1.1	break;
165			libsize++;
166			}
167	greg	2.2	if (fptr == NULL) { /* delete */
168			while (lp < &library[libsize-1]) {
169	greg	2.17	lp[0] = lp[1];
170	greg	2.2	lp++;
171			}
172			libsize--;
173			} else { /* or assign */
174			lp[0].fname = fname; /* string must be static! */
175			lp[0].nargs = nargs;
176			lp[0].atyp = assign;
177			lp[0].f = fptr;
178			}
179	greg	2.6	if (libsize != oldlibsize)
180	greg	2.32	elibupdate(fname); /* relink library */
181	greg	1.1	}
182
183
184			int
185	greg	2.16	nargum(void) /* return number of available arguments */
186	greg	1.1	{
187	greg	2.16	int n;
188	greg	1.1
189			if (curact == NULL)
190			return(0);
191			if (curact->fun == NULL) {
192			for (n = 0; (1L<<n) & curact->an; n++)
193			;
194			return(n);
195			}
196			return(nekids(curact->fun) - 1);
197			}
198
199
200			double
201	greg	2.16	argument(int n) /* return nth argument for active function */
202	greg	1.1	{
203	greg	2.16	ACTIVATION *actp = curact;
204	greg	2.30	EPNODE *ep;
205	greg	1.1	double aval;
206
207	greg	2.19	if (!actp \| (--n < 0)) {
208	greg	1.1	eputs("Bad call to argument!\n");
209			quit(1);
210			}
211	greg	2.20	if ((n < AFLAGSIZ) & actp->an >> n) /* already computed? */
212	greg	1.1	return(actp->ap[n]);
213
214	greg	2.19	if (!actp->fun \|\| !(ep = ekid(actp->fun, n+1))) {
215	greg	1.1	eputs(actp->name);
216			eputs(": too few arguments\n");
217			quit(1);
218			}
219	greg	2.19	curact = actp->prev; /* previous context */
220	greg	1.1	aval = evalue(ep); /* compute argument */
221	greg	2.20	curact = actp; /* put back calling context */
222			if (n < ALISTSIZ) { /* save value if room */
223	greg	1.1	actp->ap[n] = aval;
224			actp->an \|= 1L<<n;
225			}
226			return(aval);
227			}
228
229
230			VARDEF *
231	greg	2.32	eargf(int n) /* return function def for nth argument */
232	greg	1.1	{
233	greg	2.16	ACTIVATION *actp;
234			EPNODE *ep;
235	greg	1.1
236			for (actp = curact; actp != NULL; actp = actp->prev) {
237
238			if (n <= 0)
239			break;
240
241			if (actp->fun == NULL)
242			goto badarg;
243
244			if ((ep = ekid(actp->fun, n)) == NULL) {
245			eputs(actp->name);
246			eputs(": too few arguments\n");
247			quit(1);
248			}
249			if (ep->type == VAR)
250			return(ep->v.ln); /* found it */
251
252			if (ep->type != ARG)
253			goto badarg;
254
255			n = ep->v.chan; /* try previous context */
256			}
257	greg	2.32	eputs("Bad call to eargf!\n");
258	greg	1.1	quit(1);
259
260			badarg:
261			eputs(actp->name);
262			eputs(": argument not a function\n");
263			quit(1);
264	schorsch	2.11	return NULL; /* pro forma return */
265	greg	1.1	}
266
267
268			char *
269	greg	2.32	eargfun(int n) /* return function name for nth argument */
270	greg	1.1	{
271	greg	2.32	return(eargf(n)->name);
272	greg	1.1	}
273
274
275			double
276	greg	2.16	efunc(EPNODE ep) / evaluate a function */
277	greg	1.1	{
278			ACTIVATION act;
279			double alist[ALISTSIZ];
280			double rval;
281	greg	2.16	VARDEF *dp;
282	greg	1.1	/* push environment */
283			dp = resolve(ep->v.kid);
284			act.name = dp->name;
285			act.prev = curact;
286			act.ap = alist;
287			act.an = 0;
288			act.fun = ep;
289			curact = &act;
290
291			if (dp->def == NULL \|\| dp->def->v.kid->type != FUNC)
292			rval = libfunc(act.name, dp);
293			else
294			rval = evalue(dp->def->v.kid->sibling);
295
296			curact = act.prev; /* pop environment */
297			return(rval);
298			}
299
300
301	greg	2.30	double
302			eargument( /* evaluate an argument */
303			EPNODE *ep
304			)
305			{
306	greg	2.31	if ((ep->v.chan <= AFLAGSIZ) & curact->an >> (ep->v.chan-1))
307			return(curact->ap[ep->v.chan-1]);
308	greg	2.30
309			return(argument(ep->v.chan));
310			}
311
312
313	greg	2.32	ELIBR *
314			eliblookup(char fname) / look up a library function */
315	greg	1.1	{
316			int upper, lower;
317	greg	2.16	int cm, i;
318	greg	1.1
319			lower = 0;
320			upper = cm = libsize;
321
322			while ((i = (lower + upper) >> 1) != cm) {
323			cm = strcmp(fname, library[i].fname);
324			if (cm > 0)
325			lower = i;
326			else if (cm < 0)
327			upper = i;
328			else
329			return(&library[i]);
330			cm = i;
331			}
332			return(NULL);
333			}
334
335
336			/*
337			* The following routines are for internal use:
338			*/
339
340
341			static double
342	greg	2.16	libfunc( /* execute library function */
343			char *fname,
344			VARDEF *vp
345			)
346	greg	1.1	{
347	greg	2.32	ELIBR *lp;
348	greg	1.1	double d;
349			int lasterrno;
350
351	greg	2.3	if (vp != NULL)
352			lp = vp->lib;
353			else
354	greg	2.32	lp = eliblookup(fname);
355	greg	2.3	if (lp == NULL) {
356	greg	1.1	eputs(fname);
357			eputs(": undefined function\n");
358			quit(1);
359			}
360			lasterrno = errno;
361			errno = 0;
362	greg	2.3	d = (*lp->f)(lp->fname);
363	greg	2.15	#ifdef isnan
364	greg	2.18	if (errno == 0) {
365	greg	1.9	if (isnan(d))
366			errno = EDOM;
367			else if (isinf(d))
368			errno = ERANGE;
369	greg	2.18	}
370	greg	1.1	#endif
371	greg	2.28	if ((errno == EDOM) \| (errno == ERANGE)) {
372	greg	1.1	wputs(fname);
373	greg	1.8	if (errno == EDOM)
374			wputs(": domain error\n");
375			else if (errno == ERANGE)
376			wputs(": range error\n");
377			else
378			wputs(": error in call\n");
379	greg	1.1	return(0.0);
380			}
381			errno = lasterrno;
382			return(d);
383			}
384
385
386			/*
387			* Library functions:
388			*/
389
390
391			static double
392	greg	2.13	l_if(char nm) / if(cond, then, else) conditional expression */
393	greg	1.1	/* cond evaluates true if greater than zero */
394			{
395			if (argument(1) > 0.0)
396			return(argument(2));
397			else
398			return(argument(3));
399			}
400
401
402			static double
403	greg	2.13	l_select(char nm) / return argument #(A1+1) */
404	greg	1.1	{
405	greg	2.23	int narg = nargum();
406			double a1 = argument(1);
407			int n = (int)(a1 + .5);
408	greg	1.1
409	greg	2.28	if ((a1 < -.5) \| (n >= narg)) {
410	greg	1.1	errno = EDOM;
411			return(0.0);
412			}
413	greg	2.23	if (!n) /* asking max index? */
414			return(narg-1);
415	greg	1.1	return(argument(n+1));
416			}
417
418
419			static double
420	greg	2.21	l_max(char nm) / general maximum function */
421			{
422			int n = nargum();
423	greg	2.24	double vmax = argument(1);
424	greg	2.21
425	greg	2.27	while (n > 1) {
426			double v = argument(n--);
427	greg	2.21	if (vmax < v)
428			vmax = v;
429			}
430			return(vmax);
431			}
432
433
434			static double
435			l_min(char nm) / general minimum function */
436			{
437			int n = nargum();
438	greg	2.24	double vmin = argument(1);
439	greg	2.21
440	greg	2.27	while (n > 1) {
441			double v = argument(n--);
442	greg	2.21	if (vmin > v)
443			vmin = v;
444			}
445			return(vmin);
446			}
447
448
449			static double
450	greg	2.13	l_rand(char nm) / random function between 0 and 1 */
451	greg	1.1	{
452			double x;
453
454			x = argument(1);
455			x = 1.0/(1.0 + xx) + 2.71828182845904;
456			x += .785398163397447 - floor(x);
457			x = 1e5 / x;
458			return(x - floor(x));
459			}
460
461
462			static double
463	greg	2.13	l_floor(char nm) / return largest integer not greater than arg1 */
464	greg	1.1	{
465			return(floor(argument(1)));
466			}
467
468
469			static double
470	greg	2.13	l_ceil(char nm) / return smallest integer not less than arg1 */
471	greg	1.1	{
472			return(ceil(argument(1)));
473			}
474
475
476			static double
477	greg	2.13	l_sqrt(char *nm)
478	greg	1.1	{
479			return(sqrt(argument(1)));
480			}
481
482
483			static double
484	greg	2.13	l_sin(char *nm)
485	greg	1.1	{
486			return(sin(argument(1)));
487			}
488
489
490			static double
491	greg	2.13	l_cos(char *nm)
492	greg	1.1	{
493			return(cos(argument(1)));
494			}
495
496
497			static double
498	greg	2.13	l_tan(char *nm)
499	greg	1.1	{
500			return(tan(argument(1)));
501			}
502
503
504			static double
505	greg	2.13	l_asin(char *nm)
506	greg	1.1	{
507			return(asin(argument(1)));
508			}
509
510
511			static double
512	greg	2.13	l_acos(char *nm)
513	greg	1.1	{
514			return(acos(argument(1)));
515			}
516
517
518			static double
519	greg	2.13	l_atan(char *nm)
520	greg	1.1	{
521			return(atan(argument(1)));
522			}
523
524
525			static double
526	greg	2.13	l_atan2(char *nm)
527	greg	1.1	{
528			return(atan2(argument(1), argument(2)));
529			}
530
531
532			static double
533	greg	2.13	l_exp(char *nm)
534	greg	1.1	{
535			return(exp(argument(1)));
536			}
537
538
539			static double
540	greg	2.13	l_log(char *nm)
541	greg	1.1	{
542			return(log(argument(1)));
543			}
544
545
546			static double
547	greg	2.13	l_log10(char *nm)
548	greg	1.1	{
549			return(log10(argument(1)));
550			}