src/common/calfunc.c

/* Copyright (c) 1986 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 *  calfunc.c - routines for calcomp using functions.
 *
 *      The define BIGLIB pulls in a large number of the
 *  available math routines.
 *
 *      If VARIABLE is not defined, only library functions
 *  can be accessed.
 *
 *     4/2/86
 */

#include  <stdio.h>

#include  <errno.h>

#include  "calcomp.h"


#define  ALISTSIZ       6       /* 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();

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

static double  l_if(), l_select(), l_rand();
static double  l_floor(), l_ceil();
#ifdef  BIGLIB
static double  l_sqrt();
static double  l_sin(), l_cos(), l_tan();
static double  l_asin(), l_acos(), l_atan(), l_atan2();
static double  l_exp(), l_log(), l_log10();
#endif

#ifdef  BIGLIB
                        /* functions must be listed alphabetically */
static LIBR  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 },
    { "rand", 1, ':', l_rand },
    { "select", 1, ':', l_select },
    { "sin", 1, ':', l_sin },
    { "sqrt", 1, ':', l_sqrt },
    { "tan", 1, ':', l_tan },
};

static int  libsize = 16;

#else
                        /* functions must be listed alphabetically */
static LIBR  library[MAXLIB] = {
    { "ceil", 1, ':', l_ceil },
    { "floor", 1, ':', l_floor },
    { "if", 3, ':', l_if },
    { "rand", 1, ':', l_rand },
    { "select", 1, ':', l_select },
};

static int  libsize = 5;

#endif

extern char  *savestr(), *emalloc();

extern LIBR  *liblookup();

extern VARDEF  *argf();

#ifdef  VARIABLE
#define  resolve(ep)    ((ep)->type==VAR?(ep)->v.ln:argf((ep)->v.chan))
#else
#define  resolve(ep)    ((ep)->v.ln)
#define varlookup(name) NULL
#endif


int
fundefined(fname)               /* return # of arguments for function */
char  *fname;
{
    LIBR  *lp;
    register VARDEF  *vp;

    if ((vp = varlookup(fname)) == NULL || vp->def == NULL
                || vp->def->v.kid->type != FUNC)
        if ((lp = liblookup(fname)) == NULL)
            return(0);
        else
            return(lp->nargs);
    else
        return(nekids(vp->def->v.kid) - 1);
}


double
funvalue(fname, n, a)           /* return a function value to the user */
char  *fname;
int  n;
double  *a;
{
    ACTIVATION  act;
    register VARDEF  *vp;
    double  rval;
                                        /* push environment */
    act.name = fname;
    act.prev = curact;
    act.ap = a;
    act.an = (1L<<n)-1;
    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);
}


funset(fname, nargs, assign, fptr)      /* set a library function */
char  *fname;
int  nargs;
int  assign;
double  (*fptr)();
{
    register LIBR  *lp;

    if ((lp = liblookup(fname)) == NULL) {
        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].fname = lp[-1].fname;
                lp[0].nargs = lp[-1].nargs;
                lp[0].atyp = lp[-1].atyp;
                lp[0].f = lp[-1].f;
            } else
                break;
        libsize++;
    }
    lp[0].fname = savestr(fname);
    lp[0].nargs = nargs;
    lp[0].atyp = assign;
    lp[0].f = fptr;
}


int
nargum()                        /* return number of available arguments */
{
    register 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(n)                     /* return nth argument for active function */
register int  n;
{
    register ACTIVATION  *actp = curact;
    EPNODE  *ep;
    double  aval;

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

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


#ifdef  VARIABLE
VARDEF *
argf(n)                         /* return function def for nth argument */
int  n;
{
    register ACTIVATION  *actp;
    register 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 argf!\n");
    quit(1);

badarg:
    eputs(actp->name);
    eputs(": argument not a function\n");
    quit(1);
}


char *
argfun(n)                       /* return function name for nth argument */
int  n;
{
    return(argf(n)->name);
}
#endif


double
efunc(ep)                               /* evaluate a function */
register EPNODE  *ep;
{
    ACTIVATION  act;
    double  alist[ALISTSIZ];
    double  rval;
    register 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);
}


LIBR *
liblookup(fname)                /* look up a library function */
char  *fname;
{
    int  upper, lower;
    register 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);
}


#ifndef  VARIABLE
VARDEF *
varinsert(vname)                /* dummy variable insert */
char  *vname;
{
    register VARDEF  *vp;

    vp = (VARDEF *)emalloc(sizeof(VARDEF));
    vp->name = savestr(vname);
    vp->nlinks = 1;
    vp->def = NULL;
    vp->lib = NULL;
    vp->next = NULL;
    return(vp);
}


varfree(vp)                     /* free dummy variable */
register VARDEF  *vp;
{
    freestr(vp->name);
    efree((char *)vp);
}
#endif


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


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

    if (vp == NULL) {
        vp = &dumdef;
        vp->lib = NULL;
    }
    if (((vp->lib == NULL || strcmp(fname, vp->lib->fname)) &&
                                (vp->lib = liblookup(fname)) == NULL) ||
                vp->lib->f == NULL) {
        eputs(fname);
        eputs(": undefined function\n");
        quit(1);
    }
    lasterrno = errno;
    errno = 0;
    d = (*vp->lib->f)();
#ifdef  IEEE
    if (!finite(d))
        errno = EDOM;
#endif
    if (errno) {
        wputs(fname);
        wputs(": bad call\n");
        return(0.0);
    }
    errno = lasterrno;
    return(d);
}


/*
 *  Library functions:
 */


static double
l_if()                  /* 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()              /* return argument #(A1+1) */
{
        register int  n;

        n = argument(1) + .5;
        if (n == 0)
                return(nargum()-1);
        if (n < 1 || n > nargum()-1) {
                errno = EDOM;
                return(0.0);
        }
        return(argument(n+1));
}


static double
l_rand()                /* random function between 0 and 1 */
{
    extern double  floor();
    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()               /* return largest integer not greater than arg1 */
{
    extern double  floor();

    return(floor(argument(1)));
}


static double
l_ceil()                /* return smallest integer not less than arg1 */
{
    extern double  ceil();

    return(ceil(argument(1)));
}


#ifdef  BIGLIB
static double
l_sqrt()
{
    extern double  sqrt();

    return(sqrt(argument(1)));
}


static double
l_sin()
{
    extern double  sin();

    return(sin(argument(1)));
}


static double
l_cos()
{
    extern double  cos();

    return(cos(argument(1)));
}


static double
l_tan()
{
    extern double  tan();

    return(tan(argument(1)));
}


static double
l_asin()
{
    extern double  asin();

    return(asin(argument(1)));
}


static double
l_acos()
{
    extern double  acos();

    return(acos(argument(1)));
}


static double
l_atan()
{
    extern double  atan();

    return(atan(argument(1)));
}


static double
l_atan2()
{
    extern double  atan2();

    return(atan2(argument(1), argument(2)));
}


static double
l_exp()
{
    extern double  exp();

    return(exp(argument(1)));
}


static double
l_log()
{
    extern double  log();

    return(log(argument(1)));
}


static double
l_log10()
{
    extern double  log10();

    return(log10(argument(1)));
}
#endif
Revision:	1.4
Committed:	Tue Apr 23 15:44:39 1991 UTC (34 years, 6 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.3:	+25 -22 lines
Log Message:	changed setfunc() call to include assignment type
#	User	Rev	Content
1	greg	1.1	/* Copyright (c) 1986 Regents of the University of California */
2
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* calfunc.c - routines for calcomp using functions.
9			*
10			* The define BIGLIB pulls in a large number of the
11			* available math routines.
12			*
13			* If VARIABLE is not defined, only library functions
14			* can be accessed.
15			*
16			* 4/2/86
17			*/
18
19			#include <stdio.h>
20
21			#include <errno.h>
22
23			#include "calcomp.h"
24
25
26			#define ALISTSIZ 6 /* maximum saved argument list */
27
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	greg	1.2	static double libfunc();
39	greg	1.1
40			#define MAXLIB 64 /* maximum number of library functions */
41
42	greg	1.2	static double l_if(), l_select(), l_rand();
43			static double l_floor(), l_ceil();
44	greg	1.1	#ifdef BIGLIB
45	greg	1.2	static double l_sqrt();
46			static double l_sin(), l_cos(), l_tan();
47			static double l_asin(), l_acos(), l_atan(), l_atan2();
48			static double l_exp(), l_log(), l_log10();
49	greg	1.1	#endif
50
51			#ifdef BIGLIB
52			/* functions must be listed alphabetically */
53			static LIBR library[MAXLIB] = {
54	greg	1.4	{ "acos", 1, ':', l_acos },
55			{ "asin", 1, ':', l_asin },
56			{ "atan", 1, ':', l_atan },
57			{ "atan2", 2, ':', l_atan2 },
58			{ "ceil", 1, ':', l_ceil },
59			{ "cos", 1, ':', l_cos },
60			{ "exp", 1, ':', l_exp },
61			{ "floor", 1, ':', l_floor },
62			{ "if", 3, ':', l_if },
63			{ "log", 1, ':', l_log },
64			{ "log10", 1, ':', l_log10 },
65			{ "rand", 1, ':', l_rand },
66			{ "select", 1, ':', l_select },
67			{ "sin", 1, ':', l_sin },
68			{ "sqrt", 1, ':', l_sqrt },
69			{ "tan", 1, ':', l_tan },
70	greg	1.1	};
71
72			static int libsize = 16;
73
74			#else
75			/* functions must be listed alphabetically */
76			static LIBR library[MAXLIB] = {
77	greg	1.4	{ "ceil", 1, ':', l_ceil },
78			{ "floor", 1, ':', l_floor },
79			{ "if", 3, ':', l_if },
80			{ "rand", 1, ':', l_rand },
81			{ "select", 1, ':', l_select },
82	greg	1.1	};
83
84			static int libsize = 5;
85
86			#endif
87
88			extern char savestr(), emalloc();
89
90			extern LIBR *liblookup();
91
92			extern VARDEF *argf();
93
94			#ifdef VARIABLE
95			#define resolve(ep) ((ep)->type==VAR?(ep)->v.ln:argf((ep)->v.chan))
96			#else
97			#define resolve(ep) ((ep)->v.ln)
98			#define varlookup(name) NULL
99			#endif
100
101
102			int
103			fundefined(fname) /* return # of arguments for function */
104			char *fname;
105			{
106			LIBR *lp;
107			register VARDEF *vp;
108
109			if ((vp = varlookup(fname)) == NULL \|\| vp->def == NULL
110			\|\| vp->def->v.kid->type != FUNC)
111			if ((lp = liblookup(fname)) == NULL)
112			return(0);
113			else
114			return(lp->nargs);
115			else
116			return(nekids(vp->def->v.kid) - 1);
117			}
118
119
120			double
121			funvalue(fname, n, a) /* return a function value to the user */
122			char *fname;
123			int n;
124			double *a;
125			{
126			ACTIVATION act;
127			register VARDEF *vp;
128			double rval;
129			/* push environment */
130			act.name = fname;
131			act.prev = curact;
132			act.ap = a;
133			act.an = (1L<<n)-1;
134			act.fun = NULL;
135			curact = &act;
136
137			if ((vp = varlookup(fname)) == NULL \|\| vp->def == NULL
138			\|\| vp->def->v.kid->type != FUNC)
139			rval = libfunc(fname, vp);
140			else
141			rval = evalue(vp->def->v.kid->sibling);
142
143			curact = act.prev; /* pop environment */
144			return(rval);
145			}
146
147
148	greg	1.4	funset(fname, nargs, assign, fptr) /* set a library function */
149	greg	1.1	char *fname;
150			int nargs;
151	greg	1.4	int assign;
152	greg	1.1	double (*fptr)();
153			{
154			register LIBR *lp;
155
156			if ((lp = liblookup(fname)) == NULL) {
157			if (libsize >= MAXLIB) {
158			eputs("Too many library functons!\n");
159			quit(1);
160			}
161			for (lp = &library[libsize]; lp > library; lp--)
162			if (strcmp(lp[-1].fname, fname) > 0) {
163			lp[0].fname = lp[-1].fname;
164			lp[0].nargs = lp[-1].nargs;
165	greg	1.4	lp[0].atyp = lp[-1].atyp;
166	greg	1.1	lp[0].f = lp[-1].f;
167			} else
168			break;
169			libsize++;
170			}
171	greg	1.3	lp[0].fname = savestr(fname);
172	greg	1.1	lp[0].nargs = nargs;
173	greg	1.4	lp[0].atyp = assign;
174	greg	1.1	lp[0].f = fptr;
175			}
176
177
178			int
179			nargum() /* return number of available arguments */
180			{
181			register int n;
182
183			if (curact == NULL)
184			return(0);
185			if (curact->fun == NULL) {
186			for (n = 0; (1L<<n) & curact->an; n++)
187			;
188			return(n);
189			}
190			return(nekids(curact->fun) - 1);
191			}
192
193
194			double
195			argument(n) /* return nth argument for active function */
196			register int n;
197			{
198			register ACTIVATION *actp = curact;
199			EPNODE *ep;
200			double aval;
201
202			if (actp == NULL \|\| --n < 0) {
203			eputs("Bad call to argument!\n");
204			quit(1);
205			}
206			/* already computed? */
207			if (1L<<n & actp->an)
208			return(actp->ap[n]);
209
210			if (actp->fun == NULL \|\| (ep = ekid(actp->fun, n+1)) == NULL) {
211			eputs(actp->name);
212			eputs(": too few arguments\n");
213			quit(1);
214			}
215			curact = actp->prev; /* pop environment */
216			aval = evalue(ep); /* compute argument */
217			curact = actp; /* push back environment */
218			if (n < ALISTSIZ) { /* save value */
219			actp->ap[n] = aval;
220			actp->an \|= 1L<<n;
221			}
222			return(aval);
223			}
224
225
226			#ifdef VARIABLE
227			VARDEF *
228			argf(n) /* return function def for nth argument */
229			int n;
230			{
231			register ACTIVATION *actp;
232			register EPNODE *ep;
233
234			for (actp = curact; actp != NULL; actp = actp->prev) {
235
236			if (n <= 0)
237			break;
238
239			if (actp->fun == NULL)
240			goto badarg;
241
242			if ((ep = ekid(actp->fun, n)) == NULL) {
243			eputs(actp->name);
244			eputs(": too few arguments\n");
245			quit(1);
246			}
247			if (ep->type == VAR)
248			return(ep->v.ln); /* found it */
249
250			if (ep->type != ARG)
251			goto badarg;
252
253			n = ep->v.chan; /* try previous context */
254			}
255			eputs("Bad call to argf!\n");
256			quit(1);
257
258			badarg:
259			eputs(actp->name);
260			eputs(": argument not a function\n");
261			quit(1);
262			}
263
264
265			char *
266			argfun(n) /* return function name for nth argument */
267			int n;
268			{
269			return(argf(n)->name);
270			}
271			#endif
272
273
274			double
275			efunc(ep) /* evaluate a function */
276			register EPNODE *ep;
277			{
278			ACTIVATION act;
279			double alist[ALISTSIZ];
280			double rval;
281			register VARDEF *dp;
282			/* 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			LIBR *
302			liblookup(fname) /* look up a library function */
303			char *fname;
304			{
305			int upper, lower;
306			register int cm, i;
307
308			lower = 0;
309			upper = cm = libsize;
310
311			while ((i = (lower + upper) >> 1) != cm) {
312			cm = strcmp(fname, library[i].fname);
313			if (cm > 0)
314			lower = i;
315			else if (cm < 0)
316			upper = i;
317			else
318			return(&library[i]);
319			cm = i;
320			}
321			return(NULL);
322			}
323
324
325			#ifndef VARIABLE
326			VARDEF *
327			varinsert(vname) /* dummy variable insert */
328			char *vname;
329			{
330			register VARDEF *vp;
331
332			vp = (VARDEF *)emalloc(sizeof(VARDEF));
333			vp->name = savestr(vname);
334			vp->nlinks = 1;
335			vp->def = NULL;
336			vp->lib = NULL;
337			vp->next = NULL;
338			return(vp);
339			}
340
341
342			varfree(vp) /* free dummy variable */
343			register VARDEF *vp;
344			{
345			freestr(vp->name);
346			efree((char *)vp);
347			}
348			#endif
349
350
351
352			/*
353			* The following routines are for internal use:
354			*/
355
356
357			static double
358			libfunc(fname, vp) /* execute library function */
359			char *fname;
360			register VARDEF *vp;
361			{
362			VARDEF dumdef;
363			double d;
364			int lasterrno;
365
366			if (vp == NULL) {
367			vp = &dumdef;
368			vp->lib = NULL;
369			}
370			if (((vp->lib == NULL \|\| strcmp(fname, vp->lib->fname)) &&
371			(vp->lib = liblookup(fname)) == NULL) \|\|
372			vp->lib->f == NULL) {
373			eputs(fname);
374			eputs(": undefined function\n");
375			quit(1);
376			}
377			lasterrno = errno;
378			errno = 0;
379			d = (*vp->lib->f)();
380			#ifdef IEEE
381			if (!finite(d))
382			errno = EDOM;
383			#endif
384			if (errno) {
385			wputs(fname);
386			wputs(": bad call\n");
387			return(0.0);
388			}
389			errno = lasterrno;
390			return(d);
391			}
392
393
394			/*
395			* Library functions:
396			*/
397
398
399			static double
400			l_if() /* if(cond, then, else) conditional expression */
401			/* cond evaluates true if greater than zero */
402			{
403			if (argument(1) > 0.0)
404			return(argument(2));
405			else
406			return(argument(3));
407			}
408
409
410			static double
411			l_select() /* return argument #(A1+1) */
412			{
413			register int n;
414
415			n = argument(1) + .5;
416			if (n == 0)
417			return(nargum()-1);
418			if (n < 1 \|\| n > nargum()-1) {
419			errno = EDOM;
420			return(0.0);
421			}
422			return(argument(n+1));
423			}
424
425
426			static double
427			l_rand() /* random function between 0 and 1 */
428			{
429			extern double floor();
430			double x;
431
432			x = argument(1);
433			x = 1.0/(1.0 + xx) + 2.71828182845904;
434			x += .785398163397447 - floor(x);
435			x = 1e5 / x;
436			return(x - floor(x));
437			}
438
439
440			static double
441			l_floor() /* return largest integer not greater than arg1 */
442			{
443			extern double floor();
444
445			return(floor(argument(1)));
446			}
447
448
449			static double
450			l_ceil() /* return smallest integer not less than arg1 */
451			{
452			extern double ceil();
453
454			return(ceil(argument(1)));
455			}
456
457
458			#ifdef BIGLIB
459			static double
460			l_sqrt()
461			{
462			extern double sqrt();
463
464			return(sqrt(argument(1)));
465			}
466
467
468			static double
469			l_sin()
470			{
471			extern double sin();
472
473			return(sin(argument(1)));
474			}
475
476
477			static double
478			l_cos()
479			{
480			extern double cos();
481
482			return(cos(argument(1)));
483			}
484
485
486			static double
487			l_tan()
488			{
489			extern double tan();
490
491			return(tan(argument(1)));
492			}
493
494
495			static double
496			l_asin()
497			{
498			extern double asin();
499
500			return(asin(argument(1)));
501			}
502
503
504			static double
505			l_acos()
506			{
507			extern double acos();
508
509			return(acos(argument(1)));
510			}
511
512
513			static double
514			l_atan()
515			{
516			extern double atan();
517
518			return(atan(argument(1)));
519			}
520
521
522			static double
523			l_atan2()
524			{
525			extern double atan2();
526
527			return(atan2(argument(1), argument(2)));
528			}
529
530
531			static double
532			l_exp()
533			{
534			extern double exp();
535
536			return(exp(argument(1)));
537			}
538
539
540			static double
541			l_log()
542			{
543			extern double log();
544
545			return(log(argument(1)));
546			}
547
548
549			static double
550			l_log10()
551			{
552			extern double log10();
553
554			return(log10(argument(1)));
555			}
556			#endif