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root/radiance/ray/src/cal/tabfunc.c
Revision: 1.4
Committed: Mon Jul 14 20:02:29 2003 UTC (20 years, 5 months ago) by schorsch
Content type: text/plain
Branch: MAIN
Changes since 1.3: +5 -9 lines
Log Message:
Moved some more platform dependencies to common header files.
Included a few necessary system headers.

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: tabfunc.c,v 1.3 2003/06/26 00:58:09 schorsch Exp $";
3 #endif
4 /*
5 * Put tabular data into functions suitable for cal programs.
6 *
7 * 2/2/95 Greg Ward
8 */
9
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13 #include <math.h>
14 #include <ctype.h>
15 #include <sys/types.h>
16
17 #include "rtprocess.h" /* getpid() */
18 #include "rtmath.h"
19 #include "rtio.h"
20
21 #define isdelim(c) (isspace(c) || (c)==',')
22
23 #define MAXTAB 1024 /* maximum number of data rows */
24 #define MAXLINE 4096 /* maximum line width (characters) */
25 #define OUTFMT "%.7g" /* output format conversion string */
26
27 int interpolate = 0;
28 char *progname;
29 char **func;
30 int nfuncs;
31
32 RREAL abscissa[MAXTAB]; /* independent values (first column) */
33 RREAL (*ordinate)[MAXTAB]; /* dependent values (other columns) */
34 int tabsize = 0; /* final table size (number of rows) */
35 char locID[16]; /* local identifier (for uniqueness) */
36
37 /*extern char *fgets(), *fskip(), *absc_exp();*/
38
39 static void load_data(FILE *fp);
40 static void print_funcs(char *xe);
41 static void putlist(register RREAL *av, int al, register int pos);
42 static char * absc_exp(void);
43
44 int
45 main(
46 int argc,
47 char **argv
48 )
49 {
50 progname = argv[0];
51 argv++;
52 argc--;
53 if (argc && !strcmp(argv[0], "-i")) {
54 interpolate++;
55 puts("interp_arr2`(i,x,f):(i+1-x)*f(i)+(x-i)*f(i+1);");
56 puts("interp_arr`(x,f):if(x-1,if(f(0)-x,interp_arr2`(floor(x),x,f),f(f(0))),f(1));");
57 argv++;
58 argc--;
59 }
60 if (!argc || argv[0][0] == '-') {
61 fprintf(stderr, "Usage: %s [-i] func1 [func2 ..]\n", progname);
62 exit(1);
63 }
64 func = argv;
65 nfuncs = argc;
66 ordinate = (RREAL (*)[MAXTAB])malloc(nfuncs*MAXTAB*sizeof(RREAL));
67 if (ordinate == NULL) {
68 fprintf(stderr, "%s: not enough memory\n", progname);
69 exit(1);
70 }
71 sprintf(locID, "p%d", getpid());
72 load_data(stdin);
73 print_funcs(absc_exp());
74 exit(0);
75 }
76
77
78 static void
79 load_data( /* load tabular data from fp */
80 FILE *fp
81 )
82 {
83 int lineno;
84 char *err;
85 char inpbuf[MAXLINE];
86 register char *cp;
87 register int i;
88
89 tabsize = lineno = 0;
90 inpbuf[MAXLINE-2] = '\n';
91 while (fgets(inpbuf, MAXLINE, fp) != NULL) {
92 lineno++;
93 if (inpbuf[MAXLINE-2] != '\n') {
94 err = "line too long";
95 goto fatal;
96 }
97 if (tabsize >= MAXTAB-1) {
98 err = "too many rows";
99 goto fatal;
100 }
101 if ((cp = fskip(inpbuf)) == NULL)
102 continue; /* skip non-data lines */
103 abscissa[tabsize] = atof(inpbuf);
104 for (i = 0; i < nfuncs; i++) {
105 while (isdelim(*cp))
106 cp++;
107 if (!*cp) {
108 err = "too few columns";
109 goto fatal;
110 }
111 ordinate[i][tabsize] = atof(cp);
112 if ((cp = fskip(cp)) == NULL) {
113 err = "bad floating-point format";
114 goto fatal;
115 }
116 }
117 tabsize++;
118 }
119 return;
120 fatal:
121 fprintf(stderr, "%s: input line %d: %s\n", progname, lineno, err);
122 exit(1);
123 }
124
125
126 static char *
127 absc_exp(void) /* produce expression for abscissa */
128 {
129 static char ourexp[64];
130 double step, eps;
131 int uniform, increasing;
132 register int i;
133
134 if (tabsize < 2)
135 return("1");
136 step = abscissa[1] - abscissa[0];
137 eps = ((increasing = (step > 0)) ? 1e-3 : -1e-3) * step;
138 uniform = 1;
139 for (i = 2; i < tabsize; i++) {
140 if (uniform && fabs((abscissa[i]-abscissa[i-1]) - step) > eps)
141 uniform = 0;
142 if (!uniform && (abscissa[i-1] < abscissa[i]) != increasing) {
143 fprintf(stderr, "%s: input not a function\n",
144 progname);
145 exit(1);
146 }
147 }
148 if (uniform) {
149 if (increasing && fabs(step - 1) < eps) {
150 if (fabs(abscissa[0] - 1) < eps)
151 strcpy(ourexp, "x");
152 else
153 sprintf(ourexp, "x-%g", abscissa[0]-1);
154 } else
155 sprintf(ourexp, "(x-%g)/%g+1", abscissa[0], step);
156 } else {
157 printf("X`%s(i):select(i,", locID);
158 putlist(abscissa, tabsize, 20);
159 puts(");");
160 if (increasing) {
161 printf("fx`%s(x):if(x-%g,if(%g-x,fx2`%s(x,%d),%d),1);\n",
162 locID, abscissa[0], abscissa[tabsize-1],
163 locID, tabsize, tabsize);
164 printf("fx2`%s(x,i):if(x-X`%s(i),\n", locID, locID);
165 } else {
166 printf("fx`%s(x):if(%g-x,if(x-%g,fx2`%s(x,%d),%d),1);\n",
167 locID, abscissa[0], abscissa[tabsize-1],
168 locID, tabsize, tabsize);
169 printf("fx2`%s(x,i):if(X`%s(i)-x,\n", locID, locID);
170 }
171 printf("\ti+(x-X`%s(i))/(X`%s(i+1)-X`%s(i)),\n",
172 locID, locID, locID);
173 printf("\tfx2`%s(x,i-1));\n", locID);
174 sprintf(ourexp, "fx`%s(x)", locID);
175 }
176 return(ourexp);
177 }
178
179
180 static void
181 print_funcs( /* print functions */
182 char *xe
183 )
184 {
185 int xelen;
186 register int i;
187
188 xelen = strlen(xe);
189 for (i = 0; i < nfuncs; i++) {
190 if (func[i][0] == '\0' | func[i][0] == '0')
191 continue;
192 if (interpolate) {
193 printf("%s`%s(i):select(i,", func[i], locID);
194 putlist(ordinate[i], tabsize,
195 27+strlen(func[i]));
196 puts(");");
197 printf("%s(x):interp_arr`(%s,%s`%s);\n",
198 func[i], xe, func[i], locID);
199 } else {
200 printf("%s(x):select(%s,", func[i], xe);
201 putlist(ordinate[i], tabsize, strlen(func[i])+xelen+12);
202 puts(");");
203 }
204 }
205 }
206
207
208 static void
209 putlist( /* put out array of values */
210 register RREAL *av,
211 int al,
212 register int pos
213 )
214 {
215 char obuf[32];
216 int len;
217
218 while (al--) {
219 sprintf(obuf, OUTFMT, *av++);
220 pos += (len = strlen(obuf)+1);
221 if (pos >= 64) {
222 putchar('\n');
223 pos = len;
224 }
225 fputs(obuf, stdout);
226 if (al)
227 putchar(',');
228 }
229 }