src/rt/data.c

#ifndef lint
static const char       RCSid[] = "$Id: data.c,v 2.22 2003/07/16 01:32:53 greg Exp $";
#endif
/*
 *  data.c - routines dealing with interpolated data.
 */

#include "copyright.h"

#include  <time.h>

#include  "standard.h"
#include  "platform.h"
#include  "color.h"
#include  "resolu.h"
#include  "data.h"

                                /* picture memory usage before warning */
#ifndef PSIZWARN
#ifdef SMLMEM
#define PSIZWARN        1500000
#else
#define PSIZWARN        5000000
#endif
#endif

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

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


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


DATARRAY *
getdata(dname)                          /* get data array dname */
char  *dname;
{
        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, getrlibpath(), R_OK)) == NULL) {
                sprintf(errmsg, "cannot find data file \"%s\"", dname);
                error(USER, errmsg);
        }
        if ((fp = fopen(dfname, "r")) == NULL) {
                sprintf(errmsg, "cannot open data file \"%s\"", dfname);
                error(SYSTEM, errmsg);
        }
                                                        /* get dimensions */
        if (fgetval(fp, 'i', (char *)&asize) <= 0)
                goto scanerr;
        if (asize <= 0 | asize > MAXDDIM) {
                sprintf(errmsg, "bad number of dimensions for \"%s\"", dname);
                error(USER, errmsg);
        }
        if ((dp = (DATARRAY *)malloc(sizeof(DATARRAY))) == NULL)
                goto memerr;
        dp->name = savestr(dname);
        dp->type = DATATY;
        dp->nd = asize;
        asize = 1;
        for (i = 0; i < dp->nd; i++) {
                if (fgetval(fp, DATATY, (char *)&dp->dim[i].org) <= 0)
                        goto scanerr;
                if (fgetval(fp, DATATY, (char *)&dp->dim[i].siz) <= 0)
                        goto scanerr;
                if (fgetval(fp, 'i', (char *)&dp->dim[i].ne) <= 0)
                        goto scanerr;
                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 = (DATATYPE *)
                                        malloc(dp->dim[i].ne*sizeof(DATATYPE));
                        if (dp->dim[i].p == NULL)
                                goto memerr;
                        for (j = 0; j < dp->dim[i].ne; j++)
                                if (fgetval(fp, DATATY,
                                                (char *)&dp->dim[i].p[j]) <= 0)
                                        goto scanerr;
                        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.d = (DATATYPE *)malloc(asize*sizeof(DATATYPE))) == NULL)
                goto memerr;
        
        for (i = 0; i < asize; i++)
                if (fgetval(fp, DATATY, (char *)&dp->arr.d[i]) <= 0)
                        goto scanerr;
        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 int
headaspect(s, iap)                      /* check string for aspect ratio */
char  *s;
double  *iap;
{
        char    fmt[32];

        if (isaspect(s))
                *iap *= aspectval(s);
        else if (formatval(fmt, s) && !globmatch(PICFMT, fmt))
                *iap = 0.0;
        return(0);
}


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

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

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

        if ((fp = fopen(pfname, "r")) == NULL) {
                sprintf(errmsg, "cannot open picture file \"%s\"", pfname);
                error(SYSTEM, errmsg);
        }
        SET_FILE_BINARY(fp);
                                                /* get dimensions */
        inpaspect = 1.0;
        getheader(fp, headaspect, (char *)&inpaspect);
        if (inpaspect <= FTINY || !fgetsresolu(&inpres, fp))
                goto readerr;
        pp[0].nd = 2;
        pp[0].dim[0].ne = inpres.yr;
        pp[0].dim[1].ne = inpres.xr;
        pp[0].dim[0].org =
        pp[0].dim[1].org = 0.0;
        if (inpres.xr <= inpres.yr*inpaspect) {
                pp[0].dim[0].siz = inpaspect *
                                        (double)inpres.yr/inpres.xr;
                pp[0].dim[1].siz = 1.0;
        } else {
                pp[0].dim[0].siz = 1.0;
                pp[0].dim[1].siz = (double)inpres.xr/inpres.yr /
                                        inpaspect;
        }
        pp[0].dim[0].p = pp[0].dim[1].p = NULL;
        sl = scanlen(&inpres);                          /* allocate array */
        ns = numscans(&inpres);
        i = ns*sl*sizeof(COLR);
#if PSIZWARN
        if (i > PSIZWARN) {                             /* memory warning */
                sprintf(errmsg, "picture file \"%s\" using %d bytes of memory",
                                pname, i);
                error(WARNING, errmsg);
        }
#endif
        if ((pp[0].arr.c = (COLR *)malloc(i)) == NULL)
                goto memerr;
                                                        /* load picture */
        if ((scanin = (COLR *)malloc(sl*sizeof(COLR))) == NULL)
                goto memerr;
        for (y = 0; y < ns; y++) {
                if (freadcolrs(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);
                        copycolr(pp[0].arr.c[i], scanin[x]);
                }
        }
        free((void *)scanin);
        fclose(fp);
        i = hash(pname);
        pp[0].next = dtab[i];           /* link into picture list */
        pp[1] = pp[0];
        pp[2] = pp[0];
        pp[0].type = RED;               /* differentiate RGB records */
        pp[1].type = GRN;
        pp[2].type = BLU;
        return(dtab[i] = pp);

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


void
freedata(dta)                   /* release data array reference */
DATARRAY  *dta;
{
        DATARRAY  head;
        int  hval, nents;
        register DATARRAY  *dpl, *dp;
        register int  i;

        if (dta == NULL) {                      /* free all if NULL */
                hval = 0; nents = TABSIZ;
        } else {
                hval = hash(dta->name); nents = 1;
        }
        while (nents--) {
                head.next = dtab[hval];
                dpl = &head;
                while ((dp = dpl->next) != NULL)
                        if ((dta == NULL | dta == dp)) {
                                dpl->next = dp->next;
                                if (dp->type == DATATY)
                                        free((void *)dp->arr.d);
                                else
                                        free((void *)dp->arr.c);
                                for (i = 0; i < dp->nd; i++)
                                        if (dp->dim[i].p != NULL)
                                                free((void *)dp->dim[i].p);
                                freestr(dp->name);
                                free((void *)dp);
                        } else
                                dpl = dp;
                dtab[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, y0, y1;
                                        /* set up dimensions for recursion */
        if (dp->nd > 1) {
                sd.name = dp->name;
                sd.type = dp->type;
                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 *= (double)(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) {
                if (dp->type == DATATY) {
                        sd.arr.d = dp->arr.d + i*asize;
                        y0 = datavalue(&sd, pt+1);
                        sd.arr.d = dp->arr.d + (i+1)*asize;
                        y1 = datavalue(&sd, pt+1);
                } else {
                        sd.arr.c = dp->arr.c + i*asize;
                        y0 = datavalue(&sd, pt+1);
                        sd.arr.c = dp->arr.c + (i+1)*asize;
                        y1 = datavalue(&sd, pt+1);
                }
        } else {
                if (dp->type == DATATY) {
                        y0 = dp->arr.d[i];
                        y1 = dp->arr.d[i+1];
                } else {
                        y0 = colrval(dp->arr.c[i],dp->type);
                        y1 = colrval(dp->arr.c[i+1],dp->type);
                }
        }
        /*
         * Extrapolate as far as one division, then
         * taper off harmonically to zero.
         */
        if (x > i+2)
                return( (2*y1-y0)/(x-(i-1)) );

        if (x < i-1)
                return( (2*y0-y1)/(i-x) );

        return( y0*((i+1)-x) + y1*(x-i) );
}
Revision:	2.23
Committed:	Mon Jul 21 22:30:19 2003 UTC (20 years, 9 months ago) by schorsch
Content type:	text/plain
Branch:	MAIN
Changes since 2.22:	+3 -3 lines
Log Message:	Eliminated copystruct() macro, which is unnecessary in ANSI. Reduced ambiguity warnings for nested if/if/else clauses.
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	schorsch	2.23	static const char RCSid[] = "$Id: data.c,v 2.22 2003/07/16 01:32:53 greg Exp $";
3	greg	1.1	#endif
4			/*
5			* data.c - routines dealing with interpolated data.
6			*/
7
8	greg	2.16	#include "copyright.h"
9	greg	2.22
10			#include <time.h>
11	greg	2.15
12	greg	1.1	#include "standard.h"
13	schorsch	2.20	#include "platform.h"
14	greg	1.1	#include "color.h"
15	greg	1.11	#include "resolu.h"
16	greg	1.1	#include "data.h"
17
18	greg	2.7	/* picture memory usage before warning */
19			#ifndef PSIZWARN
20	greg	2.18	#ifdef SMLMEM
21			#define PSIZWARN 1500000
22			#else
23	gregl	2.13	#define PSIZWARN 5000000
24	greg	2.7	#endif
25			#endif
26	greg	1.1
27	greg	2.7	#ifndef TABSIZ
28	greg	2.6	#define TABSIZ 97 /* table size (prime) */
29	greg	2.7	#endif
30	greg	2.6
31			#define hash(s) (shash(s)%TABSIZ)
32
33
34			static DATARRAY dtab[TABSIZ]; / data array list */
35	greg	1.1
36
37			DATARRAY *
38			getdata(dname) /* get data array dname */
39			char *dname;
40			{
41			char *dfname;
42			FILE *fp;
43			int asize;
44	greg	1.4	register int i, j;
45	greg	1.1	register DATARRAY *dp;
46			/* look for array in list */
47	greg	2.6	for (dp = dtab[hash(dname)]; dp != NULL; dp = dp->next)
48	greg	1.1	if (!strcmp(dname, dp->name))
49			return(dp); /* found! */
50			/*
51			* If we haven't loaded the data already, we will look
52	greg	2.5	* for it in the directories specified by the library path.
53	greg	1.1	*
54			* The file has the following format:
55			*
56	greg	1.4	* N
57	greg	1.1	* beg0 end0 n0
58			* beg1 end1 n1
59			* . . .
60	greg	1.4	* begN endN nN
61	greg	1.1	* data, later dimensions changing faster
62			* . . .
63			*
64	greg	1.4	* For irregularly spaced points, the following can be
65			* substituted for begi endi ni:
66			*
67	greg	1.6	* 0 0 ni p0i p1i .. pni
68	greg	1.1	*/
69
70	greg	2.17	if ((dfname = getpath(dname, getrlibpath(), R_OK)) == NULL) {
71	greg	1.1	sprintf(errmsg, "cannot find data file \"%s\"", dname);
72			error(USER, errmsg);
73			}
74			if ((fp = fopen(dfname, "r")) == NULL) {
75			sprintf(errmsg, "cannot open data file \"%s\"", dfname);
76			error(SYSTEM, errmsg);
77			}
78			/* get dimensions */
79	greg	2.15	if (fgetval(fp, 'i', (char *)&asize) <= 0)
80	greg	1.1	goto scanerr;
81	greg	2.12	if (asize <= 0 \| asize > MAXDDIM) {
82	greg	1.1	sprintf(errmsg, "bad number of dimensions for \"%s\"", dname);
83			error(USER, errmsg);
84			}
85	greg	2.12	if ((dp = (DATARRAY *)malloc(sizeof(DATARRAY))) == NULL)
86			goto memerr;
87			dp->name = savestr(dname);
88			dp->type = DATATY;
89			dp->nd = asize;
90	greg	1.1	asize = 1;
91			for (i = 0; i < dp->nd; i++) {
92	greg	2.15	if (fgetval(fp, DATATY, (char *)&dp->dim[i].org) <= 0)
93	greg	1.6	goto scanerr;
94	greg	2.15	if (fgetval(fp, DATATY, (char *)&dp->dim[i].siz) <= 0)
95	greg	1.10	goto scanerr;
96	greg	2.15	if (fgetval(fp, 'i', (char *)&dp->dim[i].ne) <= 0)
97	greg	1.10	goto scanerr;
98	greg	1.6	if (dp->dim[i].ne < 2)
99			goto scanerr;
100			asize *= dp->dim[i].ne;
101			if ((dp->dim[i].siz -= dp->dim[i].org) == 0) {
102	greg	2.12	dp->dim[i].p = (DATATYPE *)
103			malloc(dp->dim[i].ne*sizeof(DATATYPE));
104	greg	1.4	if (dp->dim[i].p == NULL)
105			goto memerr;
106	greg	2.10	for (j = 0; j < dp->dim[i].ne; j++)
107	greg	2.15	if (fgetval(fp, DATATY,
108			(char *)&dp->dim[i].p[j]) <= 0)
109	greg	1.4	goto scanerr;
110			for (j = 1; j < dp->dim[i].ne-1; j++)
111			if ((dp->dim[i].p[j-1] < dp->dim[i].p[j]) !=
112			(dp->dim[i].p[j] < dp->dim[i].p[j+1]))
113			goto scanerr;
114			dp->dim[i].org = dp->dim[i].p[0];
115			dp->dim[i].siz = dp->dim[i].p[dp->dim[i].ne-1]
116			- dp->dim[i].p[0];
117			} else
118	greg	1.6	dp->dim[i].p = NULL;
119	greg	1.1	}
120	greg	2.12	if ((dp->arr.d = (DATATYPE )malloc(asizesizeof(DATATYPE))) == NULL)
121	greg	1.1	goto memerr;
122
123	greg	2.10	for (i = 0; i < asize; i++)
124	greg	2.15	if (fgetval(fp, DATATY, (char *)&dp->arr.d[i]) <= 0)
125	greg	1.1	goto scanerr;
126			fclose(fp);
127	greg	2.6	i = hash(dname);
128			dp->next = dtab[i];
129			return(dtab[i] = dp);
130	greg	1.1
131			memerr:
132			error(SYSTEM, "out of memory in getdata");
133			scanerr:
134			sprintf(errmsg, "%s in data file \"%s\"",
135			feof(fp) ? "unexpected EOF" : "bad format", dfname);
136			error(USER, errmsg);
137			}
138
139
140	greg	2.15	static int
141	greg	2.4	headaspect(s, iap) /* check string for aspect ratio */
142	greg	1.5	char *s;
143	greg	2.4	double *iap;
144	greg	1.5	{
145	gwlarson	2.14	char fmt[32];
146
147	greg	1.5	if (isaspect(s))
148	greg	2.4	iap = aspectval(s);
149	greg	2.15	else if (formatval(fmt, s) && !globmatch(PICFMT, fmt))
150	gwlarson	2.14	*iap = 0.0;
151			return(0);
152	greg	1.5	}
153
154
155	greg	1.1	DATARRAY *
156			getpict(pname) /* get picture pname */
157			char *pname;
158			{
159	greg	2.4	double inpaspect;
160	greg	1.1	char *pfname;
161			FILE *fp;
162	greg	2.12	COLR *scanin;
163	greg	1.11	int sl, ns;
164	greg	2.3	RESOLU inpres;
165	schorsch	2.21	RREAL loc[2];
166	greg	1.11	int y;
167			register int x, i;
168	greg	1.1	register DATARRAY *pp;
169			/* look for array in list */
170	greg	2.12	for (pp = dtab[hash(pname)]; pp != NULL; pp = pp->next)
171	greg	1.1	if (!strcmp(pname, pp->name))
172			return(pp); /* found! */
173
174	greg	2.17	if ((pfname = getpath(pname, getrlibpath(), R_OK)) == NULL) {
175	greg	1.1	sprintf(errmsg, "cannot find picture file \"%s\"", pname);
176			error(USER, errmsg);
177			}
178	greg	2.12	if ((pp = (DATARRAY )malloc(3sizeof(DATARRAY))) == NULL)
179	greg	1.1	goto memerr;
180
181	greg	2.12	pp[0].name = savestr(pname);
182	greg	1.1
183			if ((fp = fopen(pfname, "r")) == NULL) {
184			sprintf(errmsg, "cannot open picture file \"%s\"", pfname);
185			error(SYSTEM, errmsg);
186			}
187	schorsch	2.19	SET_FILE_BINARY(fp);
188	greg	1.1	/* get dimensions */
189	greg	1.5	inpaspect = 1.0;
190	greg	2.15	getheader(fp, headaspect, (char *)&inpaspect);
191	gwlarson	2.14	if (inpaspect <= FTINY \|\| !fgetsresolu(&inpres, fp))
192	greg	1.1	goto readerr;
193	greg	2.12	pp[0].nd = 2;
194			pp[0].dim[0].ne = inpres.yr;
195			pp[0].dim[1].ne = inpres.xr;
196			pp[0].dim[0].org =
197			pp[0].dim[1].org = 0.0;
198			if (inpres.xr <= inpres.yr*inpaspect) {
199			pp[0].dim[0].siz = inpaspect *
200			(double)inpres.yr/inpres.xr;
201			pp[0].dim[1].siz = 1.0;
202			} else {
203			pp[0].dim[0].siz = 1.0;
204			pp[0].dim[1].siz = (double)inpres.xr/inpres.yr /
205			inpaspect;
206			}
207			pp[0].dim[0].p = pp[0].dim[1].p = NULL;
208			sl = scanlen(&inpres); /* allocate array */
209			ns = numscans(&inpres);
210			i = nsslsizeof(COLR);
211	greg	2.7	#if PSIZWARN
212	greg	2.12	if (i > PSIZWARN) { /* memory warning */
213	greg	2.7	sprintf(errmsg, "picture file \"%s\" using %d bytes of memory",
214			pname, i);
215			error(WARNING, errmsg);
216			}
217			#endif
218	greg	2.12	if ((pp[0].arr.c = (COLR *)malloc(i)) == NULL)
219			goto memerr;
220	greg	1.1	/* load picture */
221	greg	2.12	if ((scanin = (COLR )malloc(slsizeof(COLR))) == NULL)
222	greg	1.1	goto memerr;
223	greg	1.11	for (y = 0; y < ns; y++) {
224	greg	2.12	if (freadcolrs(scanin, sl, fp) < 0)
225	greg	1.1	goto readerr;
226	greg	1.11	for (x = 0; x < sl; x++) {
227			pix2loc(loc, &inpres, x, y);
228			i = (int)(loc[1]inpres.yr)inpres.xr +
229			(int)(loc[0]*inpres.xr);
230	greg	2.12	copycolr(pp[0].arr.c[i], scanin[x]);
231	greg	1.11	}
232	greg	1.1	}
233	greg	2.15	free((void *)scanin);
234	greg	1.1	fclose(fp);
235	greg	2.6	i = hash(pname);
236	greg	2.12	pp[0].next = dtab[i]; /* link into picture list */
237	schorsch	2.23	pp[1] = pp[0];
238			pp[2] = pp[0];
239	greg	2.12	pp[0].type = RED; /* differentiate RGB records */
240			pp[1].type = GRN;
241			pp[2].type = BLU;
242			return(dtab[i] = pp);
243	greg	1.1
244			memerr:
245			error(SYSTEM, "out of memory in getpict");
246			readerr:
247			sprintf(errmsg, "bad picture file \"%s\"", pfname);
248			error(USER, errmsg);
249			}
250
251
252	greg	2.15	void
253			freedata(dta) /* release data array reference */
254			DATARRAY *dta;
255	greg	1.1	{
256	greg	2.5	DATARRAY head;
257	greg	2.6	int hval, nents;
258	greg	2.15	register DATARRAY dpl, dp;
259	greg	1.4	register int i;
260	greg	1.1
261	greg	2.15	if (dta == NULL) { /* free all if NULL */
262	greg	2.6	hval = 0; nents = TABSIZ;
263			} else {
264	greg	2.15	hval = hash(dta->name); nents = 1;
265	greg	2.6	}
266			while (nents--) {
267			head.next = dtab[hval];
268			dpl = &head;
269			while ((dp = dpl->next) != NULL)
270	greg	2.15	if ((dta == NULL \| dta == dp)) {
271	greg	2.6	dpl->next = dp->next;
272	greg	2.12	if (dp->type == DATATY)
273	greg	2.15	free((void *)dp->arr.d);
274	greg	2.12	else
275	greg	2.15	free((void *)dp->arr.c);
276	greg	2.6	for (i = 0; i < dp->nd; i++)
277			if (dp->dim[i].p != NULL)
278	greg	2.15	free((void *)dp->dim[i].p);
279	greg	2.6	freestr(dp->name);
280	greg	2.15	free((void *)dp);
281	greg	2.6	} else
282			dpl = dp;
283			dtab[hval++] = head.next;
284			}
285	greg	1.1	}
286
287
288			double
289			datavalue(dp, pt) /* interpolate data value at a point */
290			register DATARRAY *dp;
291	greg	2.3	double *pt;
292	greg	1.1	{
293			DATARRAY sd;
294			int asize;
295	greg	1.6	int lower, upper;
296	greg	1.1	register int i;
297	greg	2.9	double x, y0, y1;
298	greg	1.4	/* set up dimensions for recursion */
299	greg	2.12	if (dp->nd > 1) {
300			sd.name = dp->name;
301			sd.type = dp->type;
302			sd.nd = dp->nd - 1;
303			asize = 1;
304			for (i = 0; i < sd.nd; i++) {
305			sd.dim[i].org = dp->dim[i+1].org;
306			sd.dim[i].siz = dp->dim[i+1].siz;
307			sd.dim[i].p = dp->dim[i+1].p;
308			asize *= sd.dim[i].ne = dp->dim[i+1].ne;
309			}
310	greg	1.1	}
311	greg	1.4	/* get independent variable */
312			if (dp->dim[0].p == NULL) { /* evenly spaced points */
313			x = (pt[0] - dp->dim[0].org)/dp->dim[0].siz;
314	greg	2.9	x *= (double)(dp->dim[0].ne - 1);
315	greg	1.4	i = x;
316			if (i < 0)
317			i = 0;
318			else if (i > dp->dim[0].ne - 2)
319			i = dp->dim[0].ne - 2;
320			} else { /* unevenly spaced points */
321	greg	1.6	if (dp->dim[0].siz > 0.0) {
322			lower = 0;
323			upper = dp->dim[0].ne;
324			} else {
325			lower = dp->dim[0].ne;
326			upper = 0;
327			}
328			do {
329			i = (lower + upper) >> 1;
330			if (pt[0] >= dp->dim[0].p[i])
331			lower = i;
332	greg	1.8	else
333	greg	1.6	upper = i;
334			} while (i != (lower + upper) >> 1);
335	greg	1.8	if (i > dp->dim[0].ne - 2)
336	greg	1.4	i = dp->dim[0].ne - 2;
337			x = i + (pt[0] - dp->dim[0].p[i]) /
338			(dp->dim[0].p[i+1] - dp->dim[0].p[i]);
339			}
340			/* get dependent variable */
341	greg	2.12	if (dp->nd > 1) {
342			if (dp->type == DATATY) {
343			sd.arr.d = dp->arr.d + i*asize;
344			y0 = datavalue(&sd, pt+1);
345			sd.arr.d = dp->arr.d + (i+1)*asize;
346			y1 = datavalue(&sd, pt+1);
347			} else {
348			sd.arr.c = dp->arr.c + i*asize;
349			y0 = datavalue(&sd, pt+1);
350			sd.arr.c = dp->arr.c + (i+1)*asize;
351			y1 = datavalue(&sd, pt+1);
352			}
353	greg	1.1	} else {
354	greg	2.12	if (dp->type == DATATY) {
355			y0 = dp->arr.d[i];
356			y1 = dp->arr.d[i+1];
357			} else {
358			y0 = colrval(dp->arr.c[i],dp->type);
359			y1 = colrval(dp->arr.c[i+1],dp->type);
360			}
361	greg	1.1	}
362			/*
363			* Extrapolate as far as one division, then
364			* taper off harmonically to zero.
365			*/
366			if (x > i+2)
367	greg	2.9	return( (2*y1-y0)/(x-(i-1)) );
368	greg	1.1
369	greg	2.9	if (x < i-1)
370			return( (2*y0-y1)/(i-x) );
371
372			return( y0((i+1)-x) + y1(x-i) );
373	greg	1.1	}