xref: /freebsd/usr.bin/ministat/ministat.c (revision db612abe8df3355d1eb23bb3b50fdd97bc21e979)
1 /*
2  * ----------------------------------------------------------------------------
3  * "THE BEER-WARE LICENSE" (Revision 42):
4  * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
5  * can do whatever you want with this stuff. If we meet some day, and you think
6  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
7  * ----------------------------------------------------------------------------
8  *
9  */
10 
11 #include <sys/cdefs.h>
12 __FBSDID("$FreeBSD$");
13 
14 #include <stdio.h>
15 #include <math.h>
16 #include <err.h>
17 #include <string.h>
18 #include <stdlib.h>
19 #include <unistd.h>
20 #include <sys/ioctl.h>
21 #include <sys/queue.h>
22 #include <sys/ttycom.h>
23 
24 #define NSTUDENT 100
25 #define NCONF 6
26 double const studentpct[] = { 80, 90, 95, 98, 99, 99.5 };
27 double student [NSTUDENT + 1][NCONF] = {
28 /* inf */	{	1.282,	1.645,	1.960,	2.326,	2.576,	3.090  },
29 /* 1. */	{	3.078,	6.314,	12.706,	31.821,	63.657,	318.313  },
30 /* 2. */	{	1.886,	2.920,	4.303,	6.965,	9.925,	22.327  },
31 /* 3. */	{	1.638,	2.353,	3.182,	4.541,	5.841,	10.215  },
32 /* 4. */	{	1.533,	2.132,	2.776,	3.747,	4.604,	7.173  },
33 /* 5. */	{	1.476,	2.015,	2.571,	3.365,	4.032,	5.893  },
34 /* 6. */	{	1.440,	1.943,	2.447,	3.143,	3.707,	5.208  },
35 /* 7. */	{	1.415,	1.895,	2.365,	2.998,	3.499,	4.782  },
36 /* 8. */	{	1.397,	1.860,	2.306,	2.896,	3.355,	4.499  },
37 /* 9. */	{	1.383,	1.833,	2.262,	2.821,	3.250,	4.296  },
38 /* 10. */	{	1.372,	1.812,	2.228,	2.764,	3.169,	4.143  },
39 /* 11. */	{	1.363,	1.796,	2.201,	2.718,	3.106,	4.024  },
40 /* 12. */	{	1.356,	1.782,	2.179,	2.681,	3.055,	3.929  },
41 /* 13. */	{	1.350,	1.771,	2.160,	2.650,	3.012,	3.852  },
42 /* 14. */	{	1.345,	1.761,	2.145,	2.624,	2.977,	3.787  },
43 /* 15. */	{	1.341,	1.753,	2.131,	2.602,	2.947,	3.733  },
44 /* 16. */	{	1.337,	1.746,	2.120,	2.583,	2.921,	3.686  },
45 /* 17. */	{	1.333,	1.740,	2.110,	2.567,	2.898,	3.646  },
46 /* 18. */	{	1.330,	1.734,	2.101,	2.552,	2.878,	3.610  },
47 /* 19. */	{	1.328,	1.729,	2.093,	2.539,	2.861,	3.579  },
48 /* 20. */	{	1.325,	1.725,	2.086,	2.528,	2.845,	3.552  },
49 /* 21. */	{	1.323,	1.721,	2.080,	2.518,	2.831,	3.527  },
50 /* 22. */	{	1.321,	1.717,	2.074,	2.508,	2.819,	3.505  },
51 /* 23. */	{	1.319,	1.714,	2.069,	2.500,	2.807,	3.485  },
52 /* 24. */	{	1.318,	1.711,	2.064,	2.492,	2.797,	3.467  },
53 /* 25. */	{	1.316,	1.708,	2.060,	2.485,	2.787,	3.450  },
54 /* 26. */	{	1.315,	1.706,	2.056,	2.479,	2.779,	3.435  },
55 /* 27. */	{	1.314,	1.703,	2.052,	2.473,	2.771,	3.421  },
56 /* 28. */	{	1.313,	1.701,	2.048,	2.467,	2.763,	3.408  },
57 /* 29. */	{	1.311,	1.699,	2.045,	2.462,	2.756,	3.396  },
58 /* 30. */	{	1.310,	1.697,	2.042,	2.457,	2.750,	3.385  },
59 /* 31. */	{	1.309,	1.696,	2.040,	2.453,	2.744,	3.375  },
60 /* 32. */	{	1.309,	1.694,	2.037,	2.449,	2.738,	3.365  },
61 /* 33. */	{	1.308,	1.692,	2.035,	2.445,	2.733,	3.356  },
62 /* 34. */	{	1.307,	1.691,	2.032,	2.441,	2.728,	3.348  },
63 /* 35. */	{	1.306,	1.690,	2.030,	2.438,	2.724,	3.340  },
64 /* 36. */	{	1.306,	1.688,	2.028,	2.434,	2.719,	3.333  },
65 /* 37. */	{	1.305,	1.687,	2.026,	2.431,	2.715,	3.326  },
66 /* 38. */	{	1.304,	1.686,	2.024,	2.429,	2.712,	3.319  },
67 /* 39. */	{	1.304,	1.685,	2.023,	2.426,	2.708,	3.313  },
68 /* 40. */	{	1.303,	1.684,	2.021,	2.423,	2.704,	3.307  },
69 /* 41. */	{	1.303,	1.683,	2.020,	2.421,	2.701,	3.301  },
70 /* 42. */	{	1.302,	1.682,	2.018,	2.418,	2.698,	3.296  },
71 /* 43. */	{	1.302,	1.681,	2.017,	2.416,	2.695,	3.291  },
72 /* 44. */	{	1.301,	1.680,	2.015,	2.414,	2.692,	3.286  },
73 /* 45. */	{	1.301,	1.679,	2.014,	2.412,	2.690,	3.281  },
74 /* 46. */	{	1.300,	1.679,	2.013,	2.410,	2.687,	3.277  },
75 /* 47. */	{	1.300,	1.678,	2.012,	2.408,	2.685,	3.273  },
76 /* 48. */	{	1.299,	1.677,	2.011,	2.407,	2.682,	3.269  },
77 /* 49. */	{	1.299,	1.677,	2.010,	2.405,	2.680,	3.265  },
78 /* 50. */	{	1.299,	1.676,	2.009,	2.403,	2.678,	3.261  },
79 /* 51. */	{	1.298,	1.675,	2.008,	2.402,	2.676,	3.258  },
80 /* 52. */	{	1.298,	1.675,	2.007,	2.400,	2.674,	3.255  },
81 /* 53. */	{	1.298,	1.674,	2.006,	2.399,	2.672,	3.251  },
82 /* 54. */	{	1.297,	1.674,	2.005,	2.397,	2.670,	3.248  },
83 /* 55. */	{	1.297,	1.673,	2.004,	2.396,	2.668,	3.245  },
84 /* 56. */	{	1.297,	1.673,	2.003,	2.395,	2.667,	3.242  },
85 /* 57. */	{	1.297,	1.672,	2.002,	2.394,	2.665,	3.239  },
86 /* 58. */	{	1.296,	1.672,	2.002,	2.392,	2.663,	3.237  },
87 /* 59. */	{	1.296,	1.671,	2.001,	2.391,	2.662,	3.234  },
88 /* 60. */	{	1.296,	1.671,	2.000,	2.390,	2.660,	3.232  },
89 /* 61. */	{	1.296,	1.670,	2.000,	2.389,	2.659,	3.229  },
90 /* 62. */	{	1.295,	1.670,	1.999,	2.388,	2.657,	3.227  },
91 /* 63. */	{	1.295,	1.669,	1.998,	2.387,	2.656,	3.225  },
92 /* 64. */	{	1.295,	1.669,	1.998,	2.386,	2.655,	3.223  },
93 /* 65. */	{	1.295,	1.669,	1.997,	2.385,	2.654,	3.220  },
94 /* 66. */	{	1.295,	1.668,	1.997,	2.384,	2.652,	3.218  },
95 /* 67. */	{	1.294,	1.668,	1.996,	2.383,	2.651,	3.216  },
96 /* 68. */	{	1.294,	1.668,	1.995,	2.382,	2.650,	3.214  },
97 /* 69. */	{	1.294,	1.667,	1.995,	2.382,	2.649,	3.213  },
98 /* 70. */	{	1.294,	1.667,	1.994,	2.381,	2.648,	3.211  },
99 /* 71. */	{	1.294,	1.667,	1.994,	2.380,	2.647,	3.209  },
100 /* 72. */	{	1.293,	1.666,	1.993,	2.379,	2.646,	3.207  },
101 /* 73. */	{	1.293,	1.666,	1.993,	2.379,	2.645,	3.206  },
102 /* 74. */	{	1.293,	1.666,	1.993,	2.378,	2.644,	3.204  },
103 /* 75. */	{	1.293,	1.665,	1.992,	2.377,	2.643,	3.202  },
104 /* 76. */	{	1.293,	1.665,	1.992,	2.376,	2.642,	3.201  },
105 /* 77. */	{	1.293,	1.665,	1.991,	2.376,	2.641,	3.199  },
106 /* 78. */	{	1.292,	1.665,	1.991,	2.375,	2.640,	3.198  },
107 /* 79. */	{	1.292,	1.664,	1.990,	2.374,	2.640,	3.197  },
108 /* 80. */	{	1.292,	1.664,	1.990,	2.374,	2.639,	3.195  },
109 /* 81. */	{	1.292,	1.664,	1.990,	2.373,	2.638,	3.194  },
110 /* 82. */	{	1.292,	1.664,	1.989,	2.373,	2.637,	3.193  },
111 /* 83. */	{	1.292,	1.663,	1.989,	2.372,	2.636,	3.191  },
112 /* 84. */	{	1.292,	1.663,	1.989,	2.372,	2.636,	3.190  },
113 /* 85. */	{	1.292,	1.663,	1.988,	2.371,	2.635,	3.189  },
114 /* 86. */	{	1.291,	1.663,	1.988,	2.370,	2.634,	3.188  },
115 /* 87. */	{	1.291,	1.663,	1.988,	2.370,	2.634,	3.187  },
116 /* 88. */	{	1.291,	1.662,	1.987,	2.369,	2.633,	3.185  },
117 /* 89. */	{	1.291,	1.662,	1.987,	2.369,	2.632,	3.184  },
118 /* 90. */	{	1.291,	1.662,	1.987,	2.368,	2.632,	3.183  },
119 /* 91. */	{	1.291,	1.662,	1.986,	2.368,	2.631,	3.182  },
120 /* 92. */	{	1.291,	1.662,	1.986,	2.368,	2.630,	3.181  },
121 /* 93. */	{	1.291,	1.661,	1.986,	2.367,	2.630,	3.180  },
122 /* 94. */	{	1.291,	1.661,	1.986,	2.367,	2.629,	3.179  },
123 /* 95. */	{	1.291,	1.661,	1.985,	2.366,	2.629,	3.178  },
124 /* 96. */	{	1.290,	1.661,	1.985,	2.366,	2.628,	3.177  },
125 /* 97. */	{	1.290,	1.661,	1.985,	2.365,	2.627,	3.176  },
126 /* 98. */	{	1.290,	1.661,	1.984,	2.365,	2.627,	3.175  },
127 /* 99. */	{	1.290,	1.660,	1.984,	2.365,	2.626,	3.175  },
128 /* 100. */	{	1.290,	1.660,	1.984,	2.364,	2.626,	3.174  }
129 };
130 
131 #define	MAX_DS	8
132 static char symbol[MAX_DS] = { ' ', 'x', '+', '*', '%', '#', '@', 'O' };
133 
134 TAILQ_HEAD(pointlist, point);
135 
136 struct dataset {
137 	char *name;
138 	struct pointlist list;
139 	double sy, syy;
140 	int n;
141 };
142 
143 static struct dataset *
144 NewSet(void)
145 {
146 	struct dataset *ds;
147 
148 	ds = calloc(1, sizeof *ds);
149 	TAILQ_INIT(&ds->list);
150 	return(ds);
151 }
152 
153 struct point {
154 	TAILQ_ENTRY(point)	list;
155 	double			val;
156 };
157 
158 static void
159 AddPoint(struct dataset *ds, double a)
160 {
161 	struct point *pp, *pp2;
162 
163 	pp = calloc(1, sizeof *pp);
164 	pp->val = a;
165 
166 	ds->n++;
167 	ds->sy += a;
168 	ds->syy += a * a;
169 	if (TAILQ_EMPTY(&ds->list)) {
170 		TAILQ_INSERT_HEAD(&ds->list, pp, list);
171 		return;
172 	}
173 	TAILQ_FOREACH(pp2, &ds->list, list) {
174 		if (pp->val < pp2->val) {
175 			TAILQ_INSERT_BEFORE(pp2, pp, list);
176 			return;
177 		}
178 	}
179 	TAILQ_INSERT_TAIL(&ds->list, pp, list);
180 }
181 
182 static double
183 Min(struct dataset *ds)
184 {
185 
186 	return (TAILQ_FIRST(&ds->list)->val);
187 }
188 
189 static double
190 Max(struct dataset *ds)
191 {
192 
193 	return(TAILQ_LAST(&ds->list, pointlist)->val);
194 }
195 
196 static double
197 Avg(struct dataset *ds)
198 {
199 
200 	return(ds->sy / ds->n);
201 }
202 
203 static double
204 Median(struct dataset *ds)
205 {
206 	int even, i;
207 	struct point *p1, *p2;
208 
209 	if ((ds->n % 2) == 1) {
210 		i = (ds->n / 2) + 1;
211 		even = 0;
212 	} else {
213 		i = ds->n / 2;
214 		even = 1;
215 	}
216 	TAILQ_FOREACH(p1, &ds->list, list) {
217 		--i;
218 		if (i == 0)
219 			break;
220 	}
221 	if (even) {
222 		p2 = TAILQ_NEXT(p1, list);
223 		return ((p2->val + p1->val) / 2);
224 	}
225 	return (p1->val);
226 }
227 
228 static double
229 Var(struct dataset *ds)
230 {
231 
232 	return (ds->syy - ds->sy * ds->sy / ds->n) / (ds->n - 1.0);
233 }
234 
235 static double
236 Stddev(struct dataset *ds)
237 {
238 
239 	return sqrt(Var(ds));
240 }
241 
242 static void
243 VitalsHead(void)
244 {
245 
246 	printf("    N           Min           Max        Median           Avg        Stddev\n");
247 }
248 
249 static void
250 Vitals(struct dataset *ds, int flag)
251 {
252 
253 	printf("%c %3d %13.8g %13.8g %13.8g %13.8g %13.8g", symbol[flag],
254 	    ds->n, Min(ds), Max(ds), Median(ds), Avg(ds), Stddev(ds));
255 	printf("\n");
256 }
257 
258 static void
259 Relative(struct dataset *ds, struct dataset *rs, int confidx)
260 {
261 	double spool, s, d, e, t;
262 	int i;
263 
264 	i = ds->n + rs->n - 2;
265 	if (i > NSTUDENT)
266 		t = student[0][confidx];
267 	else
268 		t = student[i][confidx];
269 	spool = (ds->n - 1) * Var(ds) + (rs->n - 1) * Var(rs);
270 	spool /= ds->n + rs->n - 2;
271 	spool = sqrt(spool);
272 	s = spool * sqrt(1.0 / ds->n + 1.0 / rs->n);
273 	d = Avg(ds) - Avg(rs);
274 	e = t * s;
275 
276 	if (fabs(d) > e) {
277 
278 		printf("Difference at %.1f%% confidence\n", studentpct[confidx]);
279 		printf("	%g +/- %g\n", d, e);
280 		printf("	%g%% +/- %g%%\n", d * 100 / Avg(rs), e * 100 / Avg(rs));
281 		printf("	(Student's t, pooled s = %g)\n", spool);
282 	} else {
283 		printf("No difference proven at %.1f%% confidence\n",
284 		    studentpct[confidx]);
285 	}
286 }
287 
288 struct plot {
289 	double		min;
290 	double		max;
291 	double		span;
292 	int		width;
293 
294 	double		x0, dx;
295 	int		height;
296 	char		*data;
297 	char		**bar;
298 	int		separate_bars;
299 	int		num_datasets;
300 };
301 
302 static struct plot plot;
303 
304 static void
305 SetupPlot(int width, int separate, int num_datasets)
306 {
307 	struct plot *pl;
308 
309 	pl = &plot;
310 	pl->width = width;
311 	pl->height = 0;
312 	pl->data = NULL;
313 	pl->bar = NULL;
314 	pl->separate_bars = separate;
315 	pl->num_datasets = num_datasets;
316 	pl->min = 999e99;
317 	pl->max = -999e99;
318 }
319 
320 static void
321 AdjPlot(double a)
322 {
323 	struct plot *pl;
324 
325 	pl = &plot;
326 	if (a < pl->min)
327 		pl->min = a;
328 	if (a > pl->max)
329 		pl->max = a;
330 	pl->span = pl->max - pl->min;
331 	pl->dx = pl->span / (pl->width - 1.0);
332 	pl->x0 = pl->min - .5 * pl->dx;
333 }
334 
335 static void
336 DimPlot(struct dataset *ds)
337 {
338 	AdjPlot(Min(ds));
339 	AdjPlot(Max(ds));
340 	AdjPlot(Avg(ds) - Stddev(ds));
341 	AdjPlot(Avg(ds) + Stddev(ds));
342 }
343 
344 static void
345 PlotSet(struct dataset *ds, int val)
346 {
347 	struct plot *pl;
348 	struct point *pp;
349 	int i, j, m, x;
350 	int bar;
351 
352 	pl = &plot;
353 	if (pl->span == 0)
354 		return;
355 
356 	if (pl->separate_bars)
357 		bar = val-1;
358 	else
359 		bar = 0;
360 
361 	if (pl->bar == NULL) {
362 		pl->bar = malloc(sizeof(char *) * pl->num_datasets);
363 		memset(pl->bar, 0, sizeof(char*) * pl->num_datasets);
364 	}
365 	if (pl->bar[bar] == NULL) {
366 		pl->bar[bar] = malloc(pl->width);
367 		memset(pl->bar[bar], 0, pl->width);
368 	}
369 
370 	m = 1;
371 	i = -1;
372 	j = 0;
373 	TAILQ_FOREACH(pp, &ds->list, list) {
374 		x = (pp->val - pl->x0) / pl->dx;
375 		if (x == i) {
376 			j++;
377 			if (j > m)
378 				m = j;
379 		} else {
380 			j = 1;
381 			i = x;
382 		}
383 	}
384 	m += 1;
385 	if (m > pl->height) {
386 		pl->data = realloc(pl->data, pl->width * m);
387 		memset(pl->data + pl->height * pl->width, 0,
388 		    (m - pl->height) * pl->width);
389 	}
390 	pl->height = m;
391 	i = -1;
392 	TAILQ_FOREACH(pp, &ds->list, list) {
393 		x = (pp->val - pl->x0) / pl->dx;
394 		if (x == i) {
395 			j++;
396 		} else {
397 			j = 1;
398 			i = x;
399 		}
400 		pl->data[j * pl->width + x] |= val;
401 	}
402 	if (!isnan(Stddev(ds))) {
403 		x = ((Avg(ds) - Stddev(ds)) - pl->x0) / pl->dx;
404 		m = ((Avg(ds) + Stddev(ds)) - pl->x0) / pl->dx;
405 		pl->bar[bar][m] = '|';
406 		pl->bar[bar][x] = '|';
407 		for (i = x + 1; i < m; i++)
408 			if (pl->bar[bar][i] == 0)
409 				pl->bar[bar][i] = '_';
410 	}
411 	x = (Median(ds) - pl->x0) / pl->dx;
412 	pl->bar[bar][x] = 'M';
413 	x = (Avg(ds) - pl->x0) / pl->dx;
414 	pl->bar[bar][x] = 'A';
415 }
416 
417 static void
418 DumpPlot(void)
419 {
420 	struct plot *pl;
421 	int i, j, k;
422 
423 	pl = &plot;
424 	if (pl->span == 0) {
425 		printf("[no plot, span is zero width]\n");
426 		return;
427 	}
428 
429 	putchar('+');
430 	for (i = 0; i < pl->width; i++)
431 		putchar('-');
432 	putchar('+');
433 	putchar('\n');
434 	for (i = 1; i < pl->height; i++) {
435 		putchar('|');
436 		for (j = 0; j < pl->width; j++) {
437 			k = pl->data[(pl->height - i) * pl->width + j];
438 			if (k >= 0 && k < MAX_DS)
439 				putchar(symbol[k]);
440 			else
441 				printf("[%02x]", k);
442 		}
443 		putchar('|');
444 		putchar('\n');
445 	}
446 	for (i = 0; i < pl->num_datasets; i++) {
447 		if (pl->bar[i] == NULL)
448 			continue;
449 		putchar('|');
450 		for (j = 0; j < pl->width; j++) {
451 			k = pl->bar[i][j];
452 			if (k == 0)
453 				k = ' ';
454 			putchar(k);
455 		}
456 		putchar('|');
457 		putchar('\n');
458 	}
459 	putchar('+');
460 	for (i = 0; i < pl->width; i++)
461 		putchar('-');
462 	putchar('+');
463 	putchar('\n');
464 }
465 
466 
467 static struct dataset *
468 ReadSet(const char *n, int column, const char *delim)
469 {
470 	FILE *f;
471 	char buf[BUFSIZ], *p, *t;
472 	struct dataset *s;
473 	double d;
474 	int line;
475 	int i;
476 
477 	if (n == NULL) {
478 		f = stdin;
479 		n = "<stdin>";
480 	} else if (!strcmp(n, "-")) {
481 		f = stdin;
482 		n = "<stdin>";
483 	} else {
484 		f = fopen(n, "r");
485 	}
486 	if (f == NULL)
487 		err(1, "Cannot open %s", n);
488 	s = NewSet();
489 	s->name = strdup(n);
490 	line = 0;
491 	while (fgets(buf, sizeof buf, f) != NULL) {
492 		line++;
493 
494 		i = strlen(buf);
495 		if (buf[i-1] == '\n')
496 			buf[i-1] = '\0';
497 		for (i = 1, t = strtok(buf, delim);
498 		     t != NULL && *t != '#';
499 		     i++, t = strtok(NULL, delim)) {
500 			if (i == column)
501 				break;
502 		}
503 		if (t == NULL || *t == '#')
504 			continue;
505 
506 		d = strtod(t, &p);
507 		if (p != NULL && *p != '\0')
508 			err(2, "Invalid data on line %d in %s\n", line, n);
509 		if (*buf != '\0')
510 			AddPoint(s, d);
511 	}
512 	fclose(f);
513 	if (s->n < 3) {
514 		fprintf(stderr,
515 		    "Dataset %s must contain at least 3 data points\n", n);
516 		exit (2);
517 	}
518 	return (s);
519 }
520 
521 static void
522 usage(char const *whine)
523 {
524 	int i;
525 
526 	fprintf(stderr, "%s\n", whine);
527 	fprintf(stderr,
528 	    "Usage: ministat [-C column] [-c confidence] [-d delimiter(s)] [-ns] [-w width] [file [file ...]]\n");
529 	fprintf(stderr, "\tconfidence = {");
530 	for (i = 0; i < NCONF; i++) {
531 		fprintf(stderr, "%s%g%%",
532 		    i ? ", " : "",
533 		    studentpct[i]);
534 	}
535 	fprintf(stderr, "}\n");
536 	fprintf(stderr, "\t-C : column number to extract (starts and defaults to 1)\n");
537 	fprintf(stderr, "\t-d : delimiter(s) string, default to \" \\t\"\n");
538 	fprintf(stderr, "\t-n : print summary statistics only, no graph/test\n");
539 	fprintf(stderr, "\t-s : print avg/median/stddev bars on separate lines\n");
540 	fprintf(stderr, "\t-w : width of graph/test output (default 74 or terminal width)\n");
541 	exit (2);
542 }
543 
544 int
545 main(int argc, char **argv)
546 {
547 	struct dataset *ds[7];
548 	int nds;
549 	double a;
550 	const char *delim = " \t";
551 	char *p;
552 	int c, i, ci;
553 	int column = 1;
554 	int flag_s = 0;
555 	int flag_n = 0;
556 	int termwidth = 74;
557 
558 	if (isatty(STDOUT_FILENO)) {
559 		struct winsize wsz;
560 
561 		if ((p = getenv("COLUMNS")) != NULL && *p != '\0')
562 			termwidth = atoi(p);
563 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &wsz) != -1 &&
564 			 wsz.ws_col > 0)
565 			termwidth = wsz.ws_col - 2;
566 	}
567 
568 	ci = -1;
569 	while ((c = getopt(argc, argv, "C:c:d:snw:")) != -1)
570 		switch (c) {
571 		case 'C':
572 			column = strtol(optarg, &p, 10);
573 			if (p != NULL && *p != '\0')
574 				usage("Invalid column number.");
575 			if (column <= 0)
576 				usage("Column number should be positive.");
577 			break;
578 		case 'c':
579 			a = strtod(optarg, &p);
580 			if (p != NULL && *p != '\0')
581 				usage("Not a floating point number");
582 			for (i = 0; i < NCONF; i++)
583 				if (a == studentpct[i])
584 					ci = i;
585 			if (ci == -1)
586 				usage("No support for confidence level");
587 			break;
588 		case 'd':
589 			if (*optarg == '\0')
590 				usage("Can't use empty delimiter string");
591 			delim = optarg;
592 			break;
593 		case 'n':
594 			flag_n = 1;
595 			break;
596 		case 's':
597 			flag_s = 1;
598 			break;
599 		case 'w':
600 			termwidth = strtol(optarg, &p, 10);
601 			if (p != NULL && *p != '\0')
602 				usage("Invalid width, not a number.");
603 			if (termwidth < 0)
604 				usage("Unable to move beyond left margin.");
605 			break;
606 		default:
607 			usage("Unknown option");
608 			break;
609 		}
610 	if (ci == -1)
611 		ci = 2;
612 	argc -= optind;
613 	argv += optind;
614 
615 	if (argc == 0) {
616 		ds[0] = ReadSet("-", column, delim);
617 		nds = 1;
618 	} else {
619 		if (argc > (MAX_DS - 1))
620 			usage("Too many datasets.");
621 		nds = argc;
622 		for (i = 0; i < nds; i++)
623 			ds[i] = ReadSet(argv[i], column, delim);
624 	}
625 
626 	for (i = 0; i < nds; i++)
627 		printf("%c %s\n", symbol[i+1], ds[i]->name);
628 
629 	if (!flag_n) {
630 		SetupPlot(termwidth, flag_s, nds);
631 		for (i = 0; i < nds; i++)
632 			DimPlot(ds[i]);
633 		for (i = 0; i < nds; i++)
634 			PlotSet(ds[i], i + 1);
635 		DumpPlot();
636 	}
637 	VitalsHead();
638 	Vitals(ds[0], 1);
639 	for (i = 1; i < nds; i++) {
640 		Vitals(ds[i], i + 1);
641 		if (!flag_n)
642 			Relative(ds[i], ds[0], ci);
643 	}
644 	exit(0);
645 }
646