src/rt/data.c

/* Copyright (c) 1993 Regents of the University of California */

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

/*
 *  data.c - routines dealing with interpolated data.
 *
 *     6/4/86
 */

#include  "standard.h"

#include  "color.h"

#include  "resolu.h"

#include  "data.h"

                                /* picture memory usage before warning */
#ifndef PSIZWARN
#ifdef BIGMEM
#define PSIZWARN        3000000
#else
#define PSIZWARN        1000000
#endif
#endif

#ifndef TABSIZ
#define TABSIZ          97              /* table size (prime) */
#endif

#define hash(s)         (shash(s)%TABSIZ)


extern char  *fgetword();

extern char  *getlibpath();             /* library search path */

static DATARRAY  *dtab[TABSIZ];         /* data array list */

static DATARRAY  *ptab[TABSIZ];         /* picture list */


DATARRAY *
getdata(dname)                          /* get data array dname */
char  *dname;
{
        char  word[64];
        char  *dfname;
        FILE  *fp;
        int  asize;
        register int  i, j;
        register DATARRAY  *dp;
                                                /* look for array in list */
        for (dp = dtab[hash(dname)]; dp != NULL; dp = dp->next)
                if (!strcmp(dname, dp->name))
                        return(dp);             /* found! */

        /*
         *      If we haven't loaded the data already, we will look
         *  for it in the directories specified by the library path.
         *
         *      The file has the following format:
         *
         *              N
         *              beg0    end0    n0
         *              beg1    end1    n1
         *              . . .
         *              begN    endN    nN
         *              data, later dimensions changing faster
         *              . . .
         *
         *      For irregularly spaced points, the following can be
         *  substituted for begi endi ni:
         *
         *              0 0 ni p0i p1i .. pni
         */

        if ((dfname = getpath(dname, getlibpath(), R_OK)) == NULL) {
                sprintf(errmsg, "cannot find data file \"%s\"", dname);
                error(USER, errmsg);
        }
        if ((dp = (DATARRAY *)malloc(sizeof(DATARRAY))) == NULL)
                goto memerr;

        dp->name = savestr(dname);

        if ((fp = fopen(dfname, "r")) == NULL) {
                sprintf(errmsg, "cannot open data file \"%s\"", dfname);
                error(SYSTEM, errmsg);
        }
                                                        /* get dimensions */
        if (fgetword(word, sizeof(word), fp) == NULL || !isint(word))
                goto scanerr;
        dp->nd = atoi(word);
        if (dp->nd <= 0 || dp->nd > MAXDDIM) {
                sprintf(errmsg, "bad number of dimensions for \"%s\"", dname);
                error(USER, errmsg);
        }
        asize = 1;
        for (i = 0; i < dp->nd; i++) {
                if (fgetword(word, sizeof(word), fp) == NULL || !isflt(word))
                        goto scanerr;
                dp->dim[i].org = atof(word);
                if (fgetword(word, sizeof(word), fp) == NULL || !isflt(word))
                        goto scanerr;
                dp->dim[i].siz = atof(word);
                if (fgetword(word, sizeof(word), fp) == NULL || !isint(word))
                        goto scanerr;
                dp->dim[i].ne = atoi(word);
                if (dp->dim[i].ne < 2)
                        goto scanerr;
                asize *= dp->dim[i].ne;
                if ((dp->dim[i].siz -= dp->dim[i].org) == 0) {
                        dp->dim[i].p = (double *)malloc(dp->dim[i].ne*sizeof(double));
                        if (dp->dim[i].p == NULL)
                                goto memerr;
                        for (j = 0; j < dp->dim[i].ne; j++) {
                                if (fgetword(word, sizeof(word), fp) == NULL ||
                                                !isflt(word))
                                        goto scanerr;
                                dp->dim[i].p[j] = atof(word);
                        }
                        for (j = 1; j < dp->dim[i].ne-1; j++)
                                if ((dp->dim[i].p[j-1] < dp->dim[i].p[j]) !=
                                        (dp->dim[i].p[j] < dp->dim[i].p[j+1]))
                                        goto scanerr;
                        dp->dim[i].org = dp->dim[i].p[0];
                        dp->dim[i].siz = dp->dim[i].p[dp->dim[i].ne-1]
                                                - dp->dim[i].p[0];
                } else
                        dp->dim[i].p = NULL;
        }
        if ((dp->arr = (DATATYPE *)malloc(asize*sizeof(DATATYPE))) == NULL)
                goto memerr;
        
        for (i = 0; i < asize; i++) {
                if (fgetword(word, sizeof(word), fp) == NULL || !isflt(word))
                        goto scanerr;
                dp->arr[i] = atof(word);
        }
        fclose(fp);
        i = hash(dname);
        dp->next = dtab[i];
        return(dtab[i] = dp);

memerr:
        error(SYSTEM, "out of memory in getdata");
scanerr:
        sprintf(errmsg, "%s in data file \"%s\"",
                        feof(fp) ? "unexpected EOF" : "bad format", dfname);
        error(USER, errmsg);
}


static
headaspect(s, iap)                      /* check string for aspect ratio */
char  *s;
double  *iap;
{
        if (isaspect(s))
                *iap *= aspectval(s);
}


DATARRAY *
getpict(pname)                          /* get picture pname */
char  *pname;
{
        double  inpaspect;
        char  *pfname;
        FILE  *fp;
        COLOR  *scanin;
        int  sl, ns;
        RESOLU  inpres;
        FLOAT  loc[2];
        int  y;
        register int  x, i;
        register DATARRAY  *pp;
                                                /* look for array in list */
        for (pp = ptab[hash(pname)]; pp != NULL; pp = pp->next)
                if (!strcmp(pname, pp->name))
                        return(pp);             /* found! */

        if ((pfname = getpath(pname, getlibpath(), R_OK)) == NULL) {
                sprintf(errmsg, "cannot find picture file \"%s\"", pname);
                error(USER, errmsg);
        }
        if ((pp = (DATARRAY *)calloc(3, sizeof(DATARRAY))) == NULL)
                goto memerr;

        pp[0].name = 
        pp[1].name =
        pp[2].name = savestr(pname);

        if ((fp = fopen(pfname, "r")) == NULL) {
                sprintf(errmsg, "cannot open picture file \"%s\"", pfname);
                error(SYSTEM, errmsg);
        }
#ifdef MSDOS
        setmode(fileno(fp), O_BINARY);
#endif
                                                /* get dimensions */
        inpaspect = 1.0;
        getheader(fp, headaspect, &inpaspect);
        if (!fgetsresolu(&inpres, fp))
                goto readerr;
#if PSIZWARN
                                                /* check memory usage */
        i = 3*sizeof(DATATYPE)*inpres.xr*inpres.yr;
        if (i > PSIZWARN) {
                sprintf(errmsg, "picture file \"%s\" using %d bytes of memory",
                                pname, i);
                error(WARNING, errmsg);
        }
#endif
        for (i = 0; i < 3; i++) {
                pp[i].nd = 2;
                pp[i].dim[0].ne = inpres.yr;
                pp[i].dim[1].ne = inpres.xr;
                pp[i].dim[0].org =
                pp[i].dim[1].org = 0.0;
                if (inpres.xr <= inpres.yr*inpaspect) {
                        pp[i].dim[0].siz = inpaspect *
                                                (double)inpres.yr/inpres.xr;
                        pp[i].dim[1].siz = 1.0;
                } else {
                        pp[i].dim[0].siz = 1.0;
                        pp[i].dim[1].siz = (double)inpres.xr/inpres.yr /
                                                inpaspect;
                }
                pp[i].dim[0].p = pp[i].dim[1].p = NULL;
                pp[i].arr = (DATATYPE *)
                                malloc(inpres.xr*inpres.yr*sizeof(DATATYPE));
                if (pp[i].arr == NULL)
                        goto memerr;
        }
                                                        /* load picture */
        sl = scanlen(&inpres);
        ns = numscans(&inpres);
        if ((scanin = (COLOR *)malloc(sl*sizeof(COLOR))) == NULL)
                goto memerr;
        for (y = 0; y < ns; y++) {
                if (freadscan(scanin, sl, fp) < 0)
                        goto readerr;
                for (x = 0; x < sl; x++) {
                        pix2loc(loc, &inpres, x, y);
                        i = (int)(loc[1]*inpres.yr)*inpres.xr +
                                        (int)(loc[0]*inpres.xr);
                        pp[0].arr[i] = colval(scanin[x],RED);
                        pp[1].arr[i] = colval(scanin[x],GRN);
                        pp[2].arr[i] = colval(scanin[x],BLU);
                }
        }
        free((char *)scanin);
        fclose(fp);
        i = hash(pname);
        pp[0].next =
        pp[1].next =
        pp[2].next = ptab[i];
        return(ptab[i] = pp);

memerr:
        error(SYSTEM, "out of memory in getpict");
readerr:
        sprintf(errmsg, "bad picture file \"%s\"", pfname);
        error(USER, errmsg);
}


freedata(dname)                 /* free memory associated with dname */
char  *dname;
{
        DATARRAY  head;
        int  hval, nents;
        register DATARRAY  *dp, *dpl;
        register int  i;

        if (dname == NULL) {                    /* free all if NULL */
                hval = 0; nents = TABSIZ;
        } else {
                hval = hash(dname); nents = 1;
        }
        while (nents--) {
                head.next = dtab[hval];
                dpl = &head;
                while ((dp = dpl->next) != NULL)
                        if (dname == NULL || !strcmp(dname, dp->name)) {
                                dpl->next = dp->next;
                                free((char *)dp->arr);
                                for (i = 0; i < dp->nd; i++)
                                        if (dp->dim[i].p != NULL)
                                                free((char *)dp->dim[i].p);
                                freestr(dp->name);
                                free((char *)dp);
                        } else
                                dpl = dp;
                dtab[hval++] = head.next;
        }
}


freepict(pname)                 /* free memory associated with pname */
char  *pname;
{
        DATARRAY  head;
        int  hval, nents;
        register DATARRAY  *pp, *ppl;

        if (pname == NULL) {                    /* free all if NULL */
                hval = 0; nents = TABSIZ;
        } else {
                hval = hash(pname); nents = 1;
        }
        while (nents--) {
                head.next = ptab[hval];
                ppl = &head;
                while ((pp = ppl->next) != NULL)
                        if (pname == NULL || !strcmp(pname, pp->name)) {
                                ppl->next = pp->next;
                                free((char *)pp[0].arr);
                                free((char *)pp[1].arr);
                                free((char *)pp[2].arr);
                                freestr(pp[0].name);
                                free((char *)pp);
                        } else
                                ppl = pp;
                ptab[hval++] = head.next;
        }
}


double
datavalue(dp, pt)               /* interpolate data value at a point */
register DATARRAY  *dp;
double  *pt;
{
        DATARRAY  sd;
        int  asize;
        int  lower, upper;
        register int  i;
        double  x, y, y0, y1;
                                        /* set up dimensions for recursion */
        sd.nd = dp->nd - 1;
        asize = 1;
        for (i = 0; i < sd.nd; i++) {
                sd.dim[i].org = dp->dim[i+1].org;
                sd.dim[i].siz = dp->dim[i+1].siz;
                sd.dim[i].p = dp->dim[i+1].p;
                asize *= sd.dim[i].ne = dp->dim[i+1].ne;
        }
                                        /* get independent variable */
        if (dp->dim[0].p == NULL) {             /* evenly spaced points */
                x = (pt[0] - dp->dim[0].org)/dp->dim[0].siz;
                x = x * (dp->dim[0].ne - 1);
                i = x;
                if (i < 0)
                        i = 0;
                else if (i > dp->dim[0].ne - 2)
                        i = dp->dim[0].ne - 2;
        } else {                                /* unevenly spaced points */
                if (dp->dim[0].siz > 0.0) {
                        lower = 0;
                        upper = dp->dim[0].ne;
                } else {
                        lower = dp->dim[0].ne;
                        upper = 0;
                }
                do {
                        i = (lower + upper) >> 1;
                        if (pt[0] >= dp->dim[0].p[i])
                                lower = i;
                        else
                                upper = i;
                } while (i != (lower + upper) >> 1);
                if (i > dp->dim[0].ne - 2)
                        i = dp->dim[0].ne - 2;
                x = i + (pt[0] - dp->dim[0].p[i]) /
                                (dp->dim[0].p[i+1] - dp->dim[0].p[i]);
        }
                                        /* get dependent variable */
        if (dp->nd == 1) {
                y0 = dp->arr[i];
                y1 = dp->arr[i+1];
        } else {
                sd.arr = &dp->arr[i*asize];
                y0 = datavalue(&sd, pt+1);
                sd.arr = &dp->arr[(i+1)*asize];
                y1 = datavalue(&sd, pt+1);
        }
        /*
         * Extrapolate as far as one division, then
         * taper off harmonically to zero.
         */
        if (x > i+2)
                y = (2*y1-y0)/(x-i-1);
        else if (x < i-1)
                y = (2*y0-y1)/(i-x);
        else
                y = y0*((i+1)-x) + y1*(x-i);

        return(y);
}
Revision:	2.8
Committed:	Thu Apr 14 04:50:27 1994 UTC (30 years ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.7:	+3 -4 lines
Log Message:	changed extern char libpath to extern char getlibpath()
#	User	Rev	Content
1	greg	2.7	/* Copyright (c) 1993 Regents of the University of California */
2	greg	1.1
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* data.c - routines dealing with interpolated data.
9			*
10			* 6/4/86
11			*/
12
13			#include "standard.h"
14
15			#include "color.h"
16
17	greg	1.11	#include "resolu.h"
18
19	greg	1.1	#include "data.h"
20
21	greg	2.7	/* picture memory usage before warning */
22			#ifndef PSIZWARN
23			#ifdef BIGMEM
24			#define PSIZWARN 3000000
25			#else
26			#define PSIZWARN 1000000
27			#endif
28			#endif
29	greg	1.1
30	greg	2.7	#ifndef TABSIZ
31	greg	2.6	#define TABSIZ 97 /* table size (prime) */
32	greg	2.7	#endif
33	greg	2.6
34			#define hash(s) (shash(s)%TABSIZ)
35
36
37	greg	1.10	extern char *fgetword();
38
39	greg	2.8	extern char getlibpath(); / library search path */
40	greg	1.1
41	greg	2.6	static DATARRAY dtab[TABSIZ]; / data array list */
42	greg	1.1
43	greg	2.6	static DATARRAY ptab[TABSIZ]; / picture list */
44	greg	1.1
45
46			DATARRAY *
47			getdata(dname) /* get data array dname */
48			char *dname;
49			{
50	greg	1.10	char word[64];
51	greg	1.1	char *dfname;
52			FILE *fp;
53			int asize;
54	greg	1.4	register int i, j;
55	greg	1.1	register DATARRAY *dp;
56			/* look for array in list */
57	greg	2.6	for (dp = dtab[hash(dname)]; dp != NULL; dp = dp->next)
58	greg	1.1	if (!strcmp(dname, dp->name))
59			return(dp); /* found! */
60
61			/*
62			* If we haven't loaded the data already, we will look
63	greg	2.5	* for it in the directories specified by the library path.
64	greg	1.1	*
65			* The file has the following format:
66			*
67	greg	1.4	* N
68	greg	1.1	* beg0 end0 n0
69			* beg1 end1 n1
70			* . . .
71	greg	1.4	* begN endN nN
72	greg	1.1	* data, later dimensions changing faster
73			* . . .
74			*
75	greg	1.4	* For irregularly spaced points, the following can be
76			* substituted for begi endi ni:
77			*
78	greg	1.6	* 0 0 ni p0i p1i .. pni
79	greg	1.1	*/
80
81	greg	2.8	if ((dfname = getpath(dname, getlibpath(), R_OK)) == NULL) {
82	greg	1.1	sprintf(errmsg, "cannot find data file \"%s\"", dname);
83			error(USER, errmsg);
84			}
85			if ((dp = (DATARRAY *)malloc(sizeof(DATARRAY))) == NULL)
86			goto memerr;
87
88			dp->name = savestr(dname);
89
90			if ((fp = fopen(dfname, "r")) == NULL) {
91			sprintf(errmsg, "cannot open data file \"%s\"", dfname);
92			error(SYSTEM, errmsg);
93			}
94			/* get dimensions */
95	greg	1.10	if (fgetword(word, sizeof(word), fp) == NULL \|\| !isint(word))
96	greg	1.1	goto scanerr;
97	greg	1.10	dp->nd = atoi(word);
98	greg	1.9	if (dp->nd <= 0 \|\| dp->nd > MAXDDIM) {
99	greg	1.1	sprintf(errmsg, "bad number of dimensions for \"%s\"", dname);
100			error(USER, errmsg);
101			}
102			asize = 1;
103			for (i = 0; i < dp->nd; i++) {
104	greg	1.10	if (fgetword(word, sizeof(word), fp) == NULL \|\| !isflt(word))
105	greg	1.6	goto scanerr;
106	greg	1.10	dp->dim[i].org = atof(word);
107			if (fgetword(word, sizeof(word), fp) == NULL \|\| !isflt(word))
108			goto scanerr;
109			dp->dim[i].siz = atof(word);
110			if (fgetword(word, sizeof(word), fp) == NULL \|\| !isint(word))
111			goto scanerr;
112			dp->dim[i].ne = atoi(word);
113	greg	1.6	if (dp->dim[i].ne < 2)
114			goto scanerr;
115			asize *= dp->dim[i].ne;
116			if ((dp->dim[i].siz -= dp->dim[i].org) == 0) {
117	greg	1.4	dp->dim[i].p = (double )malloc(dp->dim[i].nesizeof(double));
118			if (dp->dim[i].p == NULL)
119			goto memerr;
120	greg	1.10	for (j = 0; j < dp->dim[i].ne; j++) {
121			if (fgetword(word, sizeof(word), fp) == NULL \|\|
122			!isflt(word))
123	greg	1.4	goto scanerr;
124	greg	1.10	dp->dim[i].p[j] = atof(word);
125			}
126	greg	1.4	for (j = 1; j < dp->dim[i].ne-1; j++)
127			if ((dp->dim[i].p[j-1] < dp->dim[i].p[j]) !=
128			(dp->dim[i].p[j] < dp->dim[i].p[j+1]))
129			goto scanerr;
130			dp->dim[i].org = dp->dim[i].p[0];
131			dp->dim[i].siz = dp->dim[i].p[dp->dim[i].ne-1]
132			- dp->dim[i].p[0];
133			} else
134	greg	1.6	dp->dim[i].p = NULL;
135	greg	1.1	}
136			if ((dp->arr = (DATATYPE )malloc(asizesizeof(DATATYPE))) == NULL)
137			goto memerr;
138
139	greg	1.10	for (i = 0; i < asize; i++) {
140			if (fgetword(word, sizeof(word), fp) == NULL \|\| !isflt(word))
141	greg	1.1	goto scanerr;
142	greg	1.10	dp->arr[i] = atof(word);
143			}
144	greg	1.1	fclose(fp);
145	greg	2.6	i = hash(dname);
146			dp->next = dtab[i];
147			return(dtab[i] = dp);
148	greg	1.1
149			memerr:
150			error(SYSTEM, "out of memory in getdata");
151			scanerr:
152			sprintf(errmsg, "%s in data file \"%s\"",
153			feof(fp) ? "unexpected EOF" : "bad format", dfname);
154			error(USER, errmsg);
155			}
156
157
158	greg	1.5	static
159	greg	2.4	headaspect(s, iap) /* check string for aspect ratio */
160	greg	1.5	char *s;
161	greg	2.4	double *iap;
162	greg	1.5	{
163			if (isaspect(s))
164	greg	2.4	iap = aspectval(s);
165	greg	1.5	}
166
167
168	greg	1.1	DATARRAY *
169			getpict(pname) /* get picture pname */
170			char *pname;
171			{
172	greg	2.4	double inpaspect;
173	greg	1.1	char *pfname;
174			FILE *fp;
175			COLOR *scanin;
176	greg	1.11	int sl, ns;
177	greg	2.3	RESOLU inpres;
178	greg	1.11	FLOAT loc[2];
179			int y;
180			register int x, i;
181	greg	1.1	register DATARRAY *pp;
182			/* look for array in list */
183	greg	2.6	for (pp = ptab[hash(pname)]; pp != NULL; pp = pp->next)
184	greg	1.1	if (!strcmp(pname, pp->name))
185			return(pp); /* found! */
186
187	greg	2.8	if ((pfname = getpath(pname, getlibpath(), R_OK)) == NULL) {
188	greg	1.1	sprintf(errmsg, "cannot find picture file \"%s\"", pname);
189			error(USER, errmsg);
190			}
191			if ((pp = (DATARRAY *)calloc(3, sizeof(DATARRAY))) == NULL)
192			goto memerr;
193
194			pp[0].name =
195			pp[1].name =
196			pp[2].name = savestr(pname);
197
198			if ((fp = fopen(pfname, "r")) == NULL) {
199			sprintf(errmsg, "cannot open picture file \"%s\"", pfname);
200			error(SYSTEM, errmsg);
201			}
202	greg	2.3	#ifdef MSDOS
203			setmode(fileno(fp), O_BINARY);
204			#endif
205	greg	1.1	/* get dimensions */
206	greg	1.5	inpaspect = 1.0;
207	greg	2.4	getheader(fp, headaspect, &inpaspect);
208	greg	1.11	if (!fgetsresolu(&inpres, fp))
209	greg	1.1	goto readerr;
210	greg	2.7	#if PSIZWARN
211			/* check memory usage */
212			i = 3sizeof(DATATYPE)inpres.xr*inpres.yr;
213			if (i > PSIZWARN) {
214			sprintf(errmsg, "picture file \"%s\" using %d bytes of memory",
215			pname, i);
216			error(WARNING, errmsg);
217			}
218			#endif
219	greg	1.1	for (i = 0; i < 3; i++) {
220			pp[i].nd = 2;
221	greg	1.11	pp[i].dim[0].ne = inpres.yr;
222			pp[i].dim[1].ne = inpres.xr;
223	greg	1.1	pp[i].dim[0].org =
224			pp[i].dim[1].org = 0.0;
225	greg	1.11	if (inpres.xr <= inpres.yr*inpaspect) {
226			pp[i].dim[0].siz = inpaspect *
227			(double)inpres.yr/inpres.xr;
228	greg	1.7	pp[i].dim[1].siz = 1.0;
229			} else {
230	greg	1.1	pp[i].dim[0].siz = 1.0;
231	greg	1.11	pp[i].dim[1].siz = (double)inpres.xr/inpres.yr /
232			inpaspect;
233	greg	1.1	}
234	greg	1.7	pp[i].dim[0].p = pp[i].dim[1].p = NULL;
235	greg	1.11	pp[i].arr = (DATATYPE *)
236			malloc(inpres.xrinpres.yrsizeof(DATATYPE));
237	greg	1.1	if (pp[i].arr == NULL)
238			goto memerr;
239			}
240			/* load picture */
241	greg	1.11	sl = scanlen(&inpres);
242			ns = numscans(&inpres);
243			if ((scanin = (COLOR )malloc(slsizeof(COLOR))) == NULL)
244	greg	1.1	goto memerr;
245	greg	1.11	for (y = 0; y < ns; y++) {
246			if (freadscan(scanin, sl, fp) < 0)
247	greg	1.1	goto readerr;
248	greg	1.11	for (x = 0; x < sl; x++) {
249			pix2loc(loc, &inpres, x, y);
250			i = (int)(loc[1]inpres.yr)inpres.xr +
251			(int)(loc[0]*inpres.xr);
252			pp[0].arr[i] = colval(scanin[x],RED);
253			pp[1].arr[i] = colval(scanin[x],GRN);
254			pp[2].arr[i] = colval(scanin[x],BLU);
255			}
256	greg	1.1	}
257			free((char *)scanin);
258			fclose(fp);
259	greg	2.6	i = hash(pname);
260	greg	1.1	pp[0].next =
261			pp[1].next =
262	greg	2.6	pp[2].next = ptab[i];
263			return(ptab[i] = pp);
264	greg	1.1
265			memerr:
266			error(SYSTEM, "out of memory in getpict");
267			readerr:
268			sprintf(errmsg, "bad picture file \"%s\"", pfname);
269			error(USER, errmsg);
270			}
271
272
273			freedata(dname) /* free memory associated with dname */
274			char *dname;
275			{
276	greg	2.5	DATARRAY head;
277	greg	2.6	int hval, nents;
278	greg	1.1	register DATARRAY dp, dpl;
279	greg	1.4	register int i;
280	greg	1.1
281	greg	2.6	if (dname == NULL) { /* free all if NULL */
282			hval = 0; nents = TABSIZ;
283			} else {
284			hval = hash(dname); nents = 1;
285			}
286			while (nents--) {
287			head.next = dtab[hval];
288			dpl = &head;
289			while ((dp = dpl->next) != NULL)
290			if (dname == NULL \|\| !strcmp(dname, dp->name)) {
291			dpl->next = dp->next;
292			free((char *)dp->arr);
293			for (i = 0; i < dp->nd; i++)
294			if (dp->dim[i].p != NULL)
295			free((char *)dp->dim[i].p);
296			freestr(dp->name);
297			free((char *)dp);
298			} else
299			dpl = dp;
300			dtab[hval++] = head.next;
301			}
302	greg	1.1	}
303
304
305			freepict(pname) /* free memory associated with pname */
306			char *pname;
307			{
308	greg	2.5	DATARRAY head;
309	greg	2.6	int hval, nents;
310	greg	1.1	register DATARRAY pp, ppl;
311
312	greg	2.6	if (pname == NULL) { /* free all if NULL */
313			hval = 0; nents = TABSIZ;
314			} else {
315			hval = hash(pname); nents = 1;
316			}
317			while (nents--) {
318			head.next = ptab[hval];
319			ppl = &head;
320			while ((pp = ppl->next) != NULL)
321			if (pname == NULL \|\| !strcmp(pname, pp->name)) {
322			ppl->next = pp->next;
323			free((char *)pp[0].arr);
324			free((char *)pp[1].arr);
325			free((char *)pp[2].arr);
326			freestr(pp[0].name);
327			free((char *)pp);
328			} else
329			ppl = pp;
330			ptab[hval++] = head.next;
331			}
332	greg	1.1	}
333
334
335			double
336			datavalue(dp, pt) /* interpolate data value at a point */
337			register DATARRAY *dp;
338	greg	2.3	double *pt;
339	greg	1.1	{
340			DATARRAY sd;
341			int asize;
342	greg	1.6	int lower, upper;
343	greg	1.1	register int i;
344	greg	2.3	double x, y, y0, y1;
345	greg	1.4	/* set up dimensions for recursion */
346	greg	1.1	sd.nd = dp->nd - 1;
347			asize = 1;
348			for (i = 0; i < sd.nd; i++) {
349			sd.dim[i].org = dp->dim[i+1].org;
350			sd.dim[i].siz = dp->dim[i+1].siz;
351	greg	1.4	sd.dim[i].p = dp->dim[i+1].p;
352	greg	1.1	asize *= sd.dim[i].ne = dp->dim[i+1].ne;
353			}
354	greg	1.4	/* get independent variable */
355			if (dp->dim[0].p == NULL) { /* evenly spaced points */
356			x = (pt[0] - dp->dim[0].org)/dp->dim[0].siz;
357			x = x * (dp->dim[0].ne - 1);
358			i = x;
359			if (i < 0)
360			i = 0;
361			else if (i > dp->dim[0].ne - 2)
362			i = dp->dim[0].ne - 2;
363			} else { /* unevenly spaced points */
364	greg	1.6	if (dp->dim[0].siz > 0.0) {
365			lower = 0;
366			upper = dp->dim[0].ne;
367			} else {
368			lower = dp->dim[0].ne;
369			upper = 0;
370			}
371			do {
372			i = (lower + upper) >> 1;
373			if (pt[0] >= dp->dim[0].p[i])
374			lower = i;
375	greg	1.8	else
376	greg	1.6	upper = i;
377			} while (i != (lower + upper) >> 1);
378	greg	1.8	if (i > dp->dim[0].ne - 2)
379	greg	1.4	i = dp->dim[0].ne - 2;
380			x = i + (pt[0] - dp->dim[0].p[i]) /
381			(dp->dim[0].p[i+1] - dp->dim[0].p[i]);
382			}
383			/* get dependent variable */
384	greg	1.1	if (dp->nd == 1) {
385			y0 = dp->arr[i];
386			y1 = dp->arr[i+1];
387			} else {
388			sd.arr = &dp->arr[i*asize];
389			y0 = datavalue(&sd, pt+1);
390			sd.arr = &dp->arr[(i+1)*asize];
391			y1 = datavalue(&sd, pt+1);
392			}
393			/*
394			* Extrapolate as far as one division, then
395			* taper off harmonically to zero.
396			*/
397			if (x > i+2)
398			y = (2*y1-y0)/(x-i-1);
399			else if (x < i-1)
400			y = (2*y0-y1)/(i-x);
401			else
402			y = y0((i+1)-x) + y1(x-i);
403
404			return(y);
405			}