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  *libpath;                  /* 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, libpath, 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;
{
        extern char  *libpath;
        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, libpath, 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:	2.7
Committed:	Mon Feb 8 13:12:28 1993 UTC (31 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.6:	+20 -1 lines
Log Message:	added warning for pictures using more than PSIZWARN bytes memory
#	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	1.1	extern char libpath; / library search path */
40
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	1.2	if ((dfname = getpath(dname, libpath, 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			extern char *libpath;
173	greg	2.4	double inpaspect;
174	greg	1.1	char *pfname;
175			FILE *fp;
176			COLOR *scanin;
177	greg	1.11	int sl, ns;
178	greg	2.3	RESOLU inpres;
179	greg	1.11	FLOAT loc[2];
180			int y;
181			register int x, i;
182	greg	1.1	register DATARRAY *pp;
183			/* look for array in list */
184	greg	2.6	for (pp = ptab[hash(pname)]; pp != NULL; pp = pp->next)
185	greg	1.1	if (!strcmp(pname, pp->name))
186			return(pp); /* found! */
187
188	greg	1.2	if ((pfname = getpath(pname, libpath, R_OK)) == NULL) {
189	greg	1.1	sprintf(errmsg, "cannot find picture file \"%s\"", pname);
190			error(USER, errmsg);
191			}
192			if ((pp = (DATARRAY *)calloc(3, sizeof(DATARRAY))) == NULL)
193			goto memerr;
194
195			pp[0].name =
196			pp[1].name =
197			pp[2].name = savestr(pname);
198
199			if ((fp = fopen(pfname, "r")) == NULL) {
200			sprintf(errmsg, "cannot open picture file \"%s\"", pfname);
201			error(SYSTEM, errmsg);
202			}
203	greg	2.3	#ifdef MSDOS
204			setmode(fileno(fp), O_BINARY);
205			#endif
206	greg	1.1	/* get dimensions */
207	greg	1.5	inpaspect = 1.0;
208	greg	2.4	getheader(fp, headaspect, &inpaspect);
209	greg	1.11	if (!fgetsresolu(&inpres, fp))
210	greg	1.1	goto readerr;
211	greg	2.7	#if PSIZWARN
212			/* check memory usage */
213			i = 3sizeof(DATATYPE)inpres.xr*inpres.yr;
214			if (i > PSIZWARN) {
215			sprintf(errmsg, "picture file \"%s\" using %d bytes of memory",
216			pname, i);
217			error(WARNING, errmsg);
218			}
219			#endif
220	greg	1.1	for (i = 0; i < 3; i++) {
221			pp[i].nd = 2;
222	greg	1.11	pp[i].dim[0].ne = inpres.yr;
223			pp[i].dim[1].ne = inpres.xr;
224	greg	1.1	pp[i].dim[0].org =
225			pp[i].dim[1].org = 0.0;
226	greg	1.11	if (inpres.xr <= inpres.yr*inpaspect) {
227			pp[i].dim[0].siz = inpaspect *
228			(double)inpres.yr/inpres.xr;
229	greg	1.7	pp[i].dim[1].siz = 1.0;
230			} else {
231	greg	1.1	pp[i].dim[0].siz = 1.0;
232	greg	1.11	pp[i].dim[1].siz = (double)inpres.xr/inpres.yr /
233			inpaspect;
234	greg	1.1	}
235	greg	1.7	pp[i].dim[0].p = pp[i].dim[1].p = NULL;
236	greg	1.11	pp[i].arr = (DATATYPE *)
237			malloc(inpres.xrinpres.yrsizeof(DATATYPE));
238	greg	1.1	if (pp[i].arr == NULL)
239			goto memerr;
240			}
241			/* load picture */
242	greg	1.11	sl = scanlen(&inpres);
243			ns = numscans(&inpres);
244			if ((scanin = (COLOR )malloc(slsizeof(COLOR))) == NULL)
245	greg	1.1	goto memerr;
246	greg	1.11	for (y = 0; y < ns; y++) {
247			if (freadscan(scanin, sl, fp) < 0)
248	greg	1.1	goto readerr;
249	greg	1.11	for (x = 0; x < sl; x++) {
250			pix2loc(loc, &inpres, x, y);
251			i = (int)(loc[1]inpres.yr)inpres.xr +
252			(int)(loc[0]*inpres.xr);
253			pp[0].arr[i] = colval(scanin[x],RED);
254			pp[1].arr[i] = colval(scanin[x],GRN);
255			pp[2].arr[i] = colval(scanin[x],BLU);
256			}
257	greg	1.1	}
258			free((char *)scanin);
259			fclose(fp);
260	greg	2.6	i = hash(pname);
261	greg	1.1	pp[0].next =
262			pp[1].next =
263	greg	2.6	pp[2].next = ptab[i];
264			return(ptab[i] = pp);
265	greg	1.1
266			memerr:
267			error(SYSTEM, "out of memory in getpict");
268			readerr:
269			sprintf(errmsg, "bad picture file \"%s\"", pfname);
270			error(USER, errmsg);
271			}
272
273
274			freedata(dname) /* free memory associated with dname */
275			char *dname;
276			{
277	greg	2.5	DATARRAY head;
278	greg	2.6	int hval, nents;
279	greg	1.1	register DATARRAY dp, dpl;
280	greg	1.4	register int i;
281	greg	1.1
282	greg	2.6	if (dname == NULL) { /* free all if NULL */
283			hval = 0; nents = TABSIZ;
284			} else {
285			hval = hash(dname); nents = 1;
286			}
287			while (nents--) {
288			head.next = dtab[hval];
289			dpl = &head;
290			while ((dp = dpl->next) != NULL)
291			if (dname == NULL \|\| !strcmp(dname, dp->name)) {
292			dpl->next = dp->next;
293			free((char *)dp->arr);
294			for (i = 0; i < dp->nd; i++)
295			if (dp->dim[i].p != NULL)
296			free((char *)dp->dim[i].p);
297			freestr(dp->name);
298			free((char *)dp);
299			} else
300			dpl = dp;
301			dtab[hval++] = head.next;
302			}
303	greg	1.1	}
304
305
306			freepict(pname) /* free memory associated with pname */
307			char *pname;
308			{
309	greg	2.5	DATARRAY head;
310	greg	2.6	int hval, nents;
311	greg	1.1	register DATARRAY pp, ppl;
312
313	greg	2.6	if (pname == NULL) { /* free all if NULL */
314			hval = 0; nents = TABSIZ;
315			} else {
316			hval = hash(pname); nents = 1;
317			}
318			while (nents--) {
319			head.next = ptab[hval];
320			ppl = &head;
321			while ((pp = ppl->next) != NULL)
322			if (pname == NULL \|\| !strcmp(pname, pp->name)) {
323			ppl->next = pp->next;
324			free((char *)pp[0].arr);
325			free((char *)pp[1].arr);
326			free((char *)pp[2].arr);
327			freestr(pp[0].name);
328			free((char *)pp);
329			} else
330			ppl = pp;
331			ptab[hval++] = head.next;
332			}
333	greg	1.1	}
334
335
336			double
337			datavalue(dp, pt) /* interpolate data value at a point */
338			register DATARRAY *dp;
339	greg	2.3	double *pt;
340	greg	1.1	{
341			DATARRAY sd;
342			int asize;
343	greg	1.6	int lower, upper;
344	greg	1.1	register int i;
345	greg	2.3	double x, y, y0, y1;
346	greg	1.4	/* set up dimensions for recursion */
347	greg	1.1	sd.nd = dp->nd - 1;
348			asize = 1;
349			for (i = 0; i < sd.nd; i++) {
350			sd.dim[i].org = dp->dim[i+1].org;
351			sd.dim[i].siz = dp->dim[i+1].siz;
352	greg	1.4	sd.dim[i].p = dp->dim[i+1].p;
353	greg	1.1	asize *= sd.dim[i].ne = dp->dim[i+1].ne;
354			}
355	greg	1.4	/* get independent variable */
356			if (dp->dim[0].p == NULL) { /* evenly spaced points */
357			x = (pt[0] - dp->dim[0].org)/dp->dim[0].siz;
358			x = x * (dp->dim[0].ne - 1);
359			i = x;
360			if (i < 0)
361			i = 0;
362			else if (i > dp->dim[0].ne - 2)
363			i = dp->dim[0].ne - 2;
364			} else { /* unevenly spaced points */
365	greg	1.6	if (dp->dim[0].siz > 0.0) {
366			lower = 0;
367			upper = dp->dim[0].ne;
368			} else {
369			lower = dp->dim[0].ne;
370			upper = 0;
371			}
372			do {
373			i = (lower + upper) >> 1;
374			if (pt[0] >= dp->dim[0].p[i])
375			lower = i;
376	greg	1.8	else
377	greg	1.6	upper = i;
378			} while (i != (lower + upper) >> 1);
379	greg	1.8	if (i > dp->dim[0].ne - 2)
380	greg	1.4	i = dp->dim[0].ne - 2;
381			x = i + (pt[0] - dp->dim[0].p[i]) /
382			(dp->dim[0].p[i+1] - dp->dim[0].p[i]);
383			}
384			/* get dependent variable */
385	greg	1.1	if (dp->nd == 1) {
386			y0 = dp->arr[i];
387			y1 = dp->arr[i+1];
388			} else {
389			sd.arr = &dp->arr[i*asize];
390			y0 = datavalue(&sd, pt+1);
391			sd.arr = &dp->arr[(i+1)*asize];
392			y1 = datavalue(&sd, pt+1);
393			}
394			/*
395			* Extrapolate as far as one division, then
396			* taper off harmonically to zero.
397			*/
398			if (x > i+2)
399			y = (2*y1-y0)/(x-i-1);
400			else if (x < i-1)
401			y = (2*y0-y1)/(i-x);
402			else
403			y = y0((i+1)-x) + y1(x-i);
404
405			return(y);
406			}