1 /****************************************************************************** 2 * 3 * Copyright International Business Machines Corp., 2006, 2008 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See 13 * the GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 18 * 19 * NAME 20 * libstats.c 21 * 22 * DESCRIPTION 23 * Some basic statistical analysis convenience tools. 24 * 25 * 26 * USAGE: 27 * To be included in test cases 28 * 29 * AUTHOR 30 * Darren Hart <dvhltc (at) us.ibm.com> 31 * 32 * HISTORY 33 * 2006-Oct-17: Initial version by Darren Hart 34 * 2009-Jul-22: Addition of stats_container_append function by Kiran Prakash 35 * 36 * TODO: the save routine for gnuplot plotting should be more modular... 37 * 38 *****************************************************************************/ 39 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include <string.h> 43 #include <errno.h> 44 #include <unistd.h> 45 #include <math.h> 46 #include <libstats.h> 47 #include <librttest.h> 48 49 #include "../include/realtime_config.h" 50 51 #ifndef HAVE_EXP10 52 # define exp10(x) (exp((x) * log(10))) 53 #endif 54 55 int save_stats = 0; 56 57 /* static helper functions */ 58 static int stats_record_compare(const void *a, const void *b) 59 { 60 int ret = 0; 61 stats_record_t *rec_a = (stats_record_t *) a; 62 stats_record_t *rec_b = (stats_record_t *) b; 63 if (rec_a->y < rec_b->y) 64 ret = -1; 65 else if (rec_a->y > rec_b->y) 66 ret = 1; 67 return ret; 68 } 69 70 /* function implementations */ 71 int stats_container_init(stats_container_t * data, long size) 72 { 73 data->size = size; 74 data->index = -1; 75 data->records = calloc(size, sizeof(stats_record_t)); 76 if (!data->records) 77 return -1; 78 return 0; 79 } 80 81 int stats_container_append(stats_container_t * data, stats_record_t rec) 82 { 83 int myindex = ++data->index; 84 if (myindex >= data->size) { 85 debug(DBG_ERR, "Number of elements cannot be more than %ld\n", 86 data->size); 87 data->index--; 88 return -1; 89 } 90 data->records[myindex] = rec; 91 return myindex; 92 } 93 94 int stats_container_resize(stats_container_t * data, long size) 95 { 96 stats_record_t *newrecords = 97 realloc(data->records, size * sizeof(stats_record_t)); 98 if (!newrecords) 99 return -1; 100 data->records = newrecords; 101 if (data->size < size) 102 memset(data->records + data->size, 0, size - data->size); 103 data->size = size; 104 return 0; 105 } 106 107 int stats_container_free(stats_container_t * data) 108 { 109 free(data->records); 110 return 0; 111 } 112 113 int stats_sort(stats_container_t * data, enum stats_sort_method method) 114 { 115 /* method not implemented, always ascending on y atm */ 116 qsort(data->records, data->index + 1, sizeof(stats_record_t), 117 stats_record_compare); 118 return 0; 119 } 120 121 float stats_stddev(stats_container_t * data) 122 { 123 long i; 124 float sd, avg, sum, delta; 125 long n; 126 127 sd = 0.0; 128 n = data->index + 1; 129 sum = 0.0; 130 131 /* calculate the mean */ 132 for (i = 0; i < n; i++) { 133 sum += data->records[i].y; 134 } 135 avg = sum / (float)n; 136 137 /* calculate the standard deviation */ 138 sum = 0.0; 139 for (i = 0; i < n; i++) { 140 delta = (data->records[i].y - avg); 141 sum += delta * delta; 142 } 143 sum /= n; 144 145 sd = sqrt(sum); 146 147 return sd; 148 } 149 150 float stats_avg(stats_container_t * data) 151 { 152 long i; 153 float avg, sum; 154 long n; 155 156 n = data->index + 1; 157 sum = 0.0; 158 159 /* calculate the mean */ 160 for (i = 0; i < n; i++) { 161 sum += data->records[i].y; 162 } 163 avg = sum / (float)n; 164 165 return avg; 166 } 167 168 long stats_min(stats_container_t * data) 169 { 170 long i; 171 long min; 172 long n; 173 174 n = data->index + 1; 175 176 /* calculate the mean */ 177 min = data->records[0].y; 178 for (i = 1; i < n; i++) { 179 if (data->records[i].y < min) { 180 min = data->records[i].y; 181 } 182 } 183 184 return min; 185 } 186 187 long stats_max(stats_container_t * data) 188 { 189 long i; 190 long max; 191 long n; 192 193 n = data->index + 1; 194 195 /* calculate the mean */ 196 max = data->records[0].y; 197 for (i = 1; i < n; i++) { 198 if (data->records[i].y > max) { 199 max = data->records[i].y; 200 } 201 } 202 203 return max; 204 } 205 206 int stats_quantiles_init(stats_quantiles_t * quantiles, int nines) 207 { 208 if (nines < 2) { 209 return -1; 210 } 211 quantiles->nines = nines; 212 /* allocate space for quantiles, starting with 0.99 (two nines) */ 213 quantiles->quantiles = calloc(sizeof(long), (nines - 1)); 214 if (!quantiles->quantiles) { 215 return -1; 216 } 217 return 0; 218 } 219 220 int stats_quantiles_free(stats_quantiles_t * quantiles) 221 { 222 free(quantiles->quantiles); 223 return 0; 224 } 225 226 int stats_quantiles_calc(stats_container_t * data, 227 stats_quantiles_t * quantiles) 228 { 229 int i; 230 int size; 231 int index; 232 233 // check for sufficient data size of accurate calculation 234 if (data->index < 0 || 235 (data->index + 1) < (long)exp10(quantiles->nines)) { 236 return -1; 237 } 238 239 size = data->index + 1; 240 stats_sort(data, ASCENDING_ON_Y); 241 242 for (i = 2; i <= quantiles->nines; i++) { 243 index = size - size / exp10(i); 244 quantiles->quantiles[i - 2] = data->records[index].y; 245 } 246 return 0; 247 } 248 249 void stats_quantiles_print(stats_quantiles_t * quantiles) 250 { 251 int i; 252 int fraction = 0; 253 for (i = 0; i <= quantiles->nines - 2; i++) { 254 if (i > 0) 255 fraction += 9 * exp10(i - 1); 256 printf("99.%d%% < %ld\n", fraction, quantiles->quantiles[i]); 257 } 258 } 259 260 int stats_hist(stats_container_t * hist, stats_container_t * data) 261 { 262 int i; 263 int ret; 264 long min, max, width; 265 long y, b; 266 267 ret = 0; 268 269 if (hist->size <= 0 || data->index < 0) { 270 return -1; 271 } 272 273 /* calculate the range of dataset */ 274 min = max = data->records[0].y; 275 for (i = 0; i <= data->index; i++) { 276 y = data->records[i].y; 277 if (y > max) 278 max = y; 279 if (y < min) 280 min = y; 281 } 282 283 /* define the bucket ranges */ 284 width = MAX((max - min) / hist->size, 1); 285 hist->records[0].x = min; 286 for (i = 1; i < (hist->size); i++) { 287 hist->records[i].x = min + i * width; 288 } 289 290 /* fill in the counts */ 291 for (i = 0; i <= data->index; i++) { 292 y = data->records[i].y; 293 b = MIN((y - min) / width, hist->size - 1); 294 hist->records[b].y++; 295 } 296 297 return 0; 298 } 299 300 void stats_hist_print(stats_container_t * hist) 301 { 302 long i, x; 303 for (i = 0; i < hist->size; i++) { 304 x = hist->records[i].x; 305 if (i < hist->size - 1) 306 printf("[%ld,%ld) = %ld\n", x, 307 hist->records[i + 1].x, hist->records[i].y); 308 else 309 printf("[%ld,-) = %ld\n", x, hist->records[i].y); 310 } 311 } 312 313 int stats_container_save(char *filename, char *title, char *xlabel, 314 char *ylabel, stats_container_t * data, char *mode) 315 { 316 int i; 317 int minx = 0, maxx = 0, miny = 0, maxy = 0; 318 FILE *dat_fd; 319 FILE *plt_fd; 320 char *datfile; 321 char *pltfile; 322 stats_record_t *rec; 323 324 if (!save_stats) 325 return 0; 326 327 /* generate the filenames */ 328 if (asprintf(&datfile, "%s.dat", filename) == -1) { 329 fprintf(stderr, 330 "Failed to allocate string for data filename\n"); 331 return -1; 332 } 333 if (asprintf(&pltfile, "%s.plt", filename) == -1) { 334 fprintf(stderr, 335 "Failed to allocate string for plot filename\n"); 336 return -1; 337 } 338 339 /* generate the data file */ 340 if ((dat_fd = fopen(datfile, "w")) == NULL) { 341 perror("Failed to open dat file"); 342 return -1; 343 } else { 344 minx = maxx = data->records[0].x; 345 miny = maxy = data->records[0].y; 346 for (i = 0; i <= data->index; i++) { 347 rec = &data->records[i]; 348 minx = MIN(minx, rec->x); 349 maxx = MAX(maxx, rec->x); 350 miny = MIN(miny, rec->y); 351 maxy = MAX(maxy, rec->y); 352 fprintf(dat_fd, "%ld %ld\n", rec->x, rec->y); 353 } 354 fclose(dat_fd); 355 } 356 357 /* generate the plt file */ 358 if (!(plt_fd = fopen(pltfile, "w"))) { 359 perror("Failed to open plt file"); 360 return -1; 361 } else { 362 fprintf(plt_fd, "set terminal png\n"); 363 fprintf(plt_fd, "set output \"%s.png\"\n", pltfile); 364 fprintf(plt_fd, "set title \"%s\"\n", title); 365 fprintf(plt_fd, "set xlabel \"%s\"\n", xlabel); 366 fprintf(plt_fd, "set ylabel \"%s\"\n", ylabel); 367 fprintf(plt_fd, "plot [0:%d] [0:%d] \"%s\" with %s\n", 368 maxx + 1, maxy + 1, datfile, mode); 369 fclose(plt_fd); 370 } 371 372 return 0; 373 } 374
