app-launcher/computestatsf.c

   1 #include <fcntl.h>
   2 #include <sys/ioctl.h>
   3 #include <stdio.h>
   4 #include <sys/time.h>
   5 #include <sys/types.h>
   6 #include <sys/mman.h>
   7 #include <unistd.h>
   8 #include <stdlib.h>
   9 #include <math.h>
  10
  11 char *pname;
  12 char *in_file;
  13
  14 #define DATA_COUNT      (1024*1024)
  15 double data_items[DATA_COUNT];
  16
  17 int num_data_items = 0;
  18
  19 #define BUFSIZE         1024
  20 char in_buf[BUFSIZE];
  21
  22 static int
  23 compare_double(const void *p1, const void *p2)
  24 {
  25         double val1 = *(u_int64_t *)p1;
  26         double val2 = *(u_int64_t *)p2;
  27
  28         if (val1 == val2)
  29                 return 0;
  30         if (val1 < val2)
  31                 return -1;
  32         return 1;
  33 }
  34
  35 int
  36 main(int argc, char **argv)
  37 {
  38         FILE *in_fp;
  39         double sum_x = 0;
  40         double sum_sq_x = 0;
  41         double mean;
  42         double std_dev;
  43         int i;
  44         int one_sd = 0;
  45         int two_sd = 0;
  46         int three_sd = 0;
  47         double one_sd_low, one_sd_high;
  48         double two_sd_low, two_sd_high;
  49         double three_sd_low, three_sd_high;
  50
  51         pname = argv[0];
  52         if (argc == 1)
  53                 in_fp = stdin;
  54         else {
  55                 in_file = argv[1];
  56                 in_fp = fopen(in_file, "r");
  57         }
  58         while (fgets(in_buf, BUFSIZE, in_fp)) {
  59                 if (num_data_items == DATA_COUNT) {
  60                         fprintf(stderr,
  61                                 "DATA overflow, increase size of data_items array\n");
  62                         exit(1);
  63                 }
  64                 sscanf(in_buf, "%lf", &data_items[num_data_items]);
  65 #if 0
  66                 printf("%lf\n", data_items[num_data_items]);
  67 #endif
  68                 num_data_items++;
  69         }
  70         if (num_data_items == 0) {
  71                 fprintf(stderr, "Empty input file ?\n");
  72                 exit(1);
  73         }
  74 #if 0
  75         printf("Total items %lu\n", num_data_items);
  76 #endif
  77         for (i = 0 ; i < num_data_items ; i++) {
  78                 sum_x += data_items[i];
  79                 sum_sq_x += data_items[i] * data_items[i];
  80         }
  81         mean = sum_x / num_data_items;
  82         printf("\tMean %.4f\n", mean);
  83         std_dev = sqrt((sum_sq_x / num_data_items) - (mean * mean));
  84         printf("\tStd Dev %.4f (%.4f%% of mean)\n",
  85                std_dev, (std_dev * 100.0) / mean);
  86         one_sd_low = mean - std_dev;
  87         one_sd_high = mean + std_dev;
  88         two_sd_low = mean - (2 * std_dev);
  89         two_sd_high = mean + (2 * std_dev);
  90         three_sd_low = mean - (3 * std_dev);
  91         three_sd_high = mean + (3 * std_dev);
  92         for (i = 0 ; i < num_data_items ; i++) {
  93                 if (data_items[i] >= one_sd_low &&
  94                     data_items[i] <= one_sd_high)
  95                         one_sd++;
  96                 if (data_items[i] >= two_sd_low &&
  97                     data_items[i] <= two_sd_high)
  98                         two_sd++;
  99                 if (data_items[i] >= three_sd_low &&
 100                          data_items[i] <= three_sd_high)
 101                         three_sd++;
 102         }
 103         printf("\tWithin 1 SD %.2f%%\n",
 104                ((double)one_sd * 100) / num_data_items);
 105         printf("\tWithin 2 SD %.2f%%\n",
 106                ((double)two_sd * 100) / num_data_items);
 107         printf("\tWithin 3 SD %.2f%%\n",
 108                ((double)three_sd* 100) / num_data_items);
 109         printf("\tOutside 3 SD %.2f%%\n",
 110                ((double)(num_data_items - three_sd) * 100) / num_data_items);
 111         /* Sort the data to get percentiles */
 112         qsort(data_items, num_data_items, sizeof(u_int64_t), compare_double);
 113         printf("\t50th percentile %lf\n", data_items[num_data_items / 2]);
 114         printf("\t75th percentile %lf\n", data_items[(3 * num_data_items) / 4]);
 115         printf("\t90th percentile %lf\n", data_items[(9 * num_data_items) / 10]);
 116         printf("\t99th percentile %lf\n", data_items[(99 * num_data_items) / 100]);
 117 }
 118