src/rt/data.c

#ifndef lint
static const char       RCSid[] = "$Id: data.c,v 2.19 2003/06/05 19:29:34 schorsch Exp $";
#endif
/*
 *  data.c - routines dealing with interpolated data.
 */

#include "copyright.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;
        FLOAT  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 */
        copystruct(&pp[1], &pp[0]);
        copystruct(&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:	2.20
Committed:	Sun Jun 8 12:03:10 2003 UTC (20 years, 10 months ago) by schorsch
Content type:	text/plain
Branch:	MAIN
Changes since 2.19:	+2 -1 lines
Log Message:	Reduced compile warnings/errors on Windows.
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	schorsch	2.20	static const char RCSid[] = "$Id: data.c,v 2.19 2003/06/05 19:29:34 schorsch 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	2.15
10	greg	1.1	#include "standard.h"
11	schorsch	2.20	#include "platform.h"
12	greg	1.1	#include "color.h"
13	greg	1.11	#include "resolu.h"
14	greg	1.1	#include "data.h"
15
16	greg	2.7	/* picture memory usage before warning */
17			#ifndef PSIZWARN
18	greg	2.18	#ifdef SMLMEM
19			#define PSIZWARN 1500000
20			#else
21	gregl	2.13	#define PSIZWARN 5000000
22	greg	2.7	#endif
23			#endif
24	greg	1.1
25	greg	2.7	#ifndef TABSIZ
26	greg	2.6	#define TABSIZ 97 /* table size (prime) */
27	greg	2.7	#endif
28	greg	2.6
29			#define hash(s) (shash(s)%TABSIZ)
30
31
32			static DATARRAY dtab[TABSIZ]; / data array list */
33	greg	1.1
34
35			DATARRAY *
36			getdata(dname) /* get data array dname */
37			char *dname;
38			{
39			char *dfname;
40			FILE *fp;
41			int asize;
42	greg	1.4	register int i, j;
43	greg	1.1	register DATARRAY *dp;
44			/* look for array in list */
45	greg	2.6	for (dp = dtab[hash(dname)]; dp != NULL; dp = dp->next)
46	greg	1.1	if (!strcmp(dname, dp->name))
47			return(dp); /* found! */
48			/*
49			* If we haven't loaded the data already, we will look
50	greg	2.5	* for it in the directories specified by the library path.
51	greg	1.1	*
52			* The file has the following format:
53			*
54	greg	1.4	* N
55	greg	1.1	* beg0 end0 n0
56			* beg1 end1 n1
57			* . . .
58	greg	1.4	* begN endN nN
59	greg	1.1	* data, later dimensions changing faster
60			* . . .
61			*
62	greg	1.4	* For irregularly spaced points, the following can be
63			* substituted for begi endi ni:
64			*
65	greg	1.6	* 0 0 ni p0i p1i .. pni
66	greg	1.1	*/
67
68	greg	2.17	if ((dfname = getpath(dname, getrlibpath(), R_OK)) == NULL) {
69	greg	1.1	sprintf(errmsg, "cannot find data file \"%s\"", dname);
70			error(USER, errmsg);
71			}
72			if ((fp = fopen(dfname, "r")) == NULL) {
73			sprintf(errmsg, "cannot open data file \"%s\"", dfname);
74			error(SYSTEM, errmsg);
75			}
76			/* get dimensions */
77	greg	2.15	if (fgetval(fp, 'i', (char *)&asize) <= 0)
78	greg	1.1	goto scanerr;
79	greg	2.12	if (asize <= 0 \| asize > MAXDDIM) {
80	greg	1.1	sprintf(errmsg, "bad number of dimensions for \"%s\"", dname);
81			error(USER, errmsg);
82			}
83	greg	2.12	if ((dp = (DATARRAY *)malloc(sizeof(DATARRAY))) == NULL)
84			goto memerr;
85			dp->name = savestr(dname);
86			dp->type = DATATY;
87			dp->nd = asize;
88	greg	1.1	asize = 1;
89			for (i = 0; i < dp->nd; i++) {
90	greg	2.15	if (fgetval(fp, DATATY, (char *)&dp->dim[i].org) <= 0)
91	greg	1.6	goto scanerr;
92	greg	2.15	if (fgetval(fp, DATATY, (char *)&dp->dim[i].siz) <= 0)
93	greg	1.10	goto scanerr;
94	greg	2.15	if (fgetval(fp, 'i', (char *)&dp->dim[i].ne) <= 0)
95	greg	1.10	goto scanerr;
96	greg	1.6	if (dp->dim[i].ne < 2)
97			goto scanerr;
98			asize *= dp->dim[i].ne;
99			if ((dp->dim[i].siz -= dp->dim[i].org) == 0) {
100	greg	2.12	dp->dim[i].p = (DATATYPE *)
101			malloc(dp->dim[i].ne*sizeof(DATATYPE));
102	greg	1.4	if (dp->dim[i].p == NULL)
103			goto memerr;
104	greg	2.10	for (j = 0; j < dp->dim[i].ne; j++)
105	greg	2.15	if (fgetval(fp, DATATY,
106			(char *)&dp->dim[i].p[j]) <= 0)
107	greg	1.4	goto scanerr;
108			for (j = 1; j < dp->dim[i].ne-1; j++)
109			if ((dp->dim[i].p[j-1] < dp->dim[i].p[j]) !=
110			(dp->dim[i].p[j] < dp->dim[i].p[j+1]))
111			goto scanerr;
112			dp->dim[i].org = dp->dim[i].p[0];
113			dp->dim[i].siz = dp->dim[i].p[dp->dim[i].ne-1]
114			- dp->dim[i].p[0];
115			} else
116	greg	1.6	dp->dim[i].p = NULL;
117	greg	1.1	}
118	greg	2.12	if ((dp->arr.d = (DATATYPE )malloc(asizesizeof(DATATYPE))) == NULL)
119	greg	1.1	goto memerr;
120
121	greg	2.10	for (i = 0; i < asize; i++)
122	greg	2.15	if (fgetval(fp, DATATY, (char *)&dp->arr.d[i]) <= 0)
123	greg	1.1	goto scanerr;
124			fclose(fp);
125	greg	2.6	i = hash(dname);
126			dp->next = dtab[i];
127			return(dtab[i] = dp);
128	greg	1.1
129			memerr:
130			error(SYSTEM, "out of memory in getdata");
131			scanerr:
132			sprintf(errmsg, "%s in data file \"%s\"",
133			feof(fp) ? "unexpected EOF" : "bad format", dfname);
134			error(USER, errmsg);
135			}
136
137
138	greg	2.15	static int
139	greg	2.4	headaspect(s, iap) /* check string for aspect ratio */
140	greg	1.5	char *s;
141	greg	2.4	double *iap;
142	greg	1.5	{
143	gwlarson	2.14	char fmt[32];
144
145	greg	1.5	if (isaspect(s))
146	greg	2.4	iap = aspectval(s);
147	greg	2.15	else if (formatval(fmt, s) && !globmatch(PICFMT, fmt))
148	gwlarson	2.14	*iap = 0.0;
149			return(0);
150	greg	1.5	}
151
152
153	greg	1.1	DATARRAY *
154			getpict(pname) /* get picture pname */
155			char *pname;
156			{
157	greg	2.4	double inpaspect;
158	greg	1.1	char *pfname;
159			FILE *fp;
160	greg	2.12	COLR *scanin;
161	greg	1.11	int sl, ns;
162	greg	2.3	RESOLU inpres;
163	greg	1.11	FLOAT loc[2];
164			int y;
165			register int x, i;
166	greg	1.1	register DATARRAY *pp;
167			/* look for array in list */
168	greg	2.12	for (pp = dtab[hash(pname)]; pp != NULL; pp = pp->next)
169	greg	1.1	if (!strcmp(pname, pp->name))
170			return(pp); /* found! */
171
172	greg	2.17	if ((pfname = getpath(pname, getrlibpath(), R_OK)) == NULL) {
173	greg	1.1	sprintf(errmsg, "cannot find picture file \"%s\"", pname);
174			error(USER, errmsg);
175			}
176	greg	2.12	if ((pp = (DATARRAY )malloc(3sizeof(DATARRAY))) == NULL)
177	greg	1.1	goto memerr;
178
179	greg	2.12	pp[0].name = savestr(pname);
180	greg	1.1
181			if ((fp = fopen(pfname, "r")) == NULL) {
182			sprintf(errmsg, "cannot open picture file \"%s\"", pfname);
183			error(SYSTEM, errmsg);
184			}
185	schorsch	2.19	SET_FILE_BINARY(fp);
186	greg	1.1	/* get dimensions */
187	greg	1.5	inpaspect = 1.0;
188	greg	2.15	getheader(fp, headaspect, (char *)&inpaspect);
189	gwlarson	2.14	if (inpaspect <= FTINY \|\| !fgetsresolu(&inpres, fp))
190	greg	1.1	goto readerr;
191	greg	2.12	pp[0].nd = 2;
192			pp[0].dim[0].ne = inpres.yr;
193			pp[0].dim[1].ne = inpres.xr;
194			pp[0].dim[0].org =
195			pp[0].dim[1].org = 0.0;
196			if (inpres.xr <= inpres.yr*inpaspect) {
197			pp[0].dim[0].siz = inpaspect *
198			(double)inpres.yr/inpres.xr;
199			pp[0].dim[1].siz = 1.0;
200			} else {
201			pp[0].dim[0].siz = 1.0;
202			pp[0].dim[1].siz = (double)inpres.xr/inpres.yr /
203			inpaspect;
204			}
205			pp[0].dim[0].p = pp[0].dim[1].p = NULL;
206			sl = scanlen(&inpres); /* allocate array */
207			ns = numscans(&inpres);
208			i = nsslsizeof(COLR);
209	greg	2.7	#if PSIZWARN
210	greg	2.12	if (i > PSIZWARN) { /* memory warning */
211	greg	2.7	sprintf(errmsg, "picture file \"%s\" using %d bytes of memory",
212			pname, i);
213			error(WARNING, errmsg);
214			}
215			#endif
216	greg	2.12	if ((pp[0].arr.c = (COLR *)malloc(i)) == NULL)
217			goto memerr;
218	greg	1.1	/* load picture */
219	greg	2.12	if ((scanin = (COLR )malloc(slsizeof(COLR))) == NULL)
220	greg	1.1	goto memerr;
221	greg	1.11	for (y = 0; y < ns; y++) {
222	greg	2.12	if (freadcolrs(scanin, sl, fp) < 0)
223	greg	1.1	goto readerr;
224	greg	1.11	for (x = 0; x < sl; x++) {
225			pix2loc(loc, &inpres, x, y);
226			i = (int)(loc[1]inpres.yr)inpres.xr +
227			(int)(loc[0]*inpres.xr);
228	greg	2.12	copycolr(pp[0].arr.c[i], scanin[x]);
229	greg	1.11	}
230	greg	1.1	}
231	greg	2.15	free((void *)scanin);
232	greg	1.1	fclose(fp);
233	greg	2.6	i = hash(pname);
234	greg	2.12	pp[0].next = dtab[i]; /* link into picture list */
235			copystruct(&pp[1], &pp[0]);
236			copystruct(&pp[2], &pp[0]);
237			pp[0].type = RED; /* differentiate RGB records */
238			pp[1].type = GRN;
239			pp[2].type = BLU;
240			return(dtab[i] = pp);
241	greg	1.1
242			memerr:
243			error(SYSTEM, "out of memory in getpict");
244			readerr:
245			sprintf(errmsg, "bad picture file \"%s\"", pfname);
246			error(USER, errmsg);
247			}
248
249
250	greg	2.15	void
251			freedata(dta) /* release data array reference */
252			DATARRAY *dta;
253	greg	1.1	{
254	greg	2.5	DATARRAY head;
255	greg	2.6	int hval, nents;
256	greg	2.15	register DATARRAY dpl, dp;
257	greg	1.4	register int i;
258	greg	1.1
259	greg	2.15	if (dta == NULL) { /* free all if NULL */
260	greg	2.6	hval = 0; nents = TABSIZ;
261			} else {
262	greg	2.15	hval = hash(dta->name); nents = 1;
263	greg	2.6	}
264			while (nents--) {
265			head.next = dtab[hval];
266			dpl = &head;
267			while ((dp = dpl->next) != NULL)
268	greg	2.15	if ((dta == NULL \| dta == dp)) {
269	greg	2.6	dpl->next = dp->next;
270	greg	2.12	if (dp->type == DATATY)
271	greg	2.15	free((void *)dp->arr.d);
272	greg	2.12	else
273	greg	2.15	free((void *)dp->arr.c);
274	greg	2.6	for (i = 0; i < dp->nd; i++)
275			if (dp->dim[i].p != NULL)
276	greg	2.15	free((void *)dp->dim[i].p);
277	greg	2.6	freestr(dp->name);
278	greg	2.15	free((void *)dp);
279	greg	2.6	} else
280			dpl = dp;
281			dtab[hval++] = head.next;
282			}
283	greg	1.1	}
284
285
286			double
287			datavalue(dp, pt) /* interpolate data value at a point */
288			register DATARRAY *dp;
289	greg	2.3	double *pt;
290	greg	1.1	{
291			DATARRAY sd;
292			int asize;
293	greg	1.6	int lower, upper;
294	greg	1.1	register int i;
295	greg	2.9	double x, y0, y1;
296	greg	1.4	/* set up dimensions for recursion */
297	greg	2.12	if (dp->nd > 1) {
298			sd.name = dp->name;
299			sd.type = dp->type;
300			sd.nd = dp->nd - 1;
301			asize = 1;
302			for (i = 0; i < sd.nd; i++) {
303			sd.dim[i].org = dp->dim[i+1].org;
304			sd.dim[i].siz = dp->dim[i+1].siz;
305			sd.dim[i].p = dp->dim[i+1].p;
306			asize *= sd.dim[i].ne = dp->dim[i+1].ne;
307			}
308	greg	1.1	}
309	greg	1.4	/* get independent variable */
310			if (dp->dim[0].p == NULL) { /* evenly spaced points */
311			x = (pt[0] - dp->dim[0].org)/dp->dim[0].siz;
312	greg	2.9	x *= (double)(dp->dim[0].ne - 1);
313	greg	1.4	i = x;
314			if (i < 0)
315			i = 0;
316			else if (i > dp->dim[0].ne - 2)
317			i = dp->dim[0].ne - 2;
318			} else { /* unevenly spaced points */
319	greg	1.6	if (dp->dim[0].siz > 0.0) {
320			lower = 0;
321			upper = dp->dim[0].ne;
322			} else {
323			lower = dp->dim[0].ne;
324			upper = 0;
325			}
326			do {
327			i = (lower + upper) >> 1;
328			if (pt[0] >= dp->dim[0].p[i])
329			lower = i;
330	greg	1.8	else
331	greg	1.6	upper = i;
332			} while (i != (lower + upper) >> 1);
333	greg	1.8	if (i > dp->dim[0].ne - 2)
334	greg	1.4	i = dp->dim[0].ne - 2;
335			x = i + (pt[0] - dp->dim[0].p[i]) /
336			(dp->dim[0].p[i+1] - dp->dim[0].p[i]);
337			}
338			/* get dependent variable */
339	greg	2.12	if (dp->nd > 1) {
340			if (dp->type == DATATY) {
341			sd.arr.d = dp->arr.d + i*asize;
342			y0 = datavalue(&sd, pt+1);
343			sd.arr.d = dp->arr.d + (i+1)*asize;
344			y1 = datavalue(&sd, pt+1);
345			} else {
346			sd.arr.c = dp->arr.c + i*asize;
347			y0 = datavalue(&sd, pt+1);
348			sd.arr.c = dp->arr.c + (i+1)*asize;
349			y1 = datavalue(&sd, pt+1);
350			}
351	greg	1.1	} else {
352	greg	2.12	if (dp->type == DATATY) {
353			y0 = dp->arr.d[i];
354			y1 = dp->arr.d[i+1];
355			} else {
356			y0 = colrval(dp->arr.c[i],dp->type);
357			y1 = colrval(dp->arr.c[i+1],dp->type);
358			}
359	greg	1.1	}
360			/*
361			* Extrapolate as far as one division, then
362			* taper off harmonically to zero.
363			*/
364			if (x > i+2)
365	greg	2.9	return( (2*y1-y0)/(x-(i-1)) );
366	greg	1.1
367	greg	2.9	if (x < i-1)
368			return( (2*y0-y1)/(i-x) );
369
370			return( y0((i+1)-x) + y1(x-i) );
371	greg	1.1	}