| 1 | #include <math.h> |
| 2 | #include <stdint.h> |
| 3 | #include <stdio.h> |
| 4 | #include <stdlib.h> |
| 5 | |
| 6 | #include "../lib/types.h" |
| 7 | #include "../lib/rand.h" |
| 8 | #include "../log.h" |
| 9 | |
| 10 | int main(int argc, char *argv[]) |
| 11 | { |
| 12 | struct frand_state s; |
| 13 | uint64_t i, start, end, nvalues; |
| 14 | unsigned long *buckets, index, pass, fail; |
| 15 | double p, dev, mean, vmin, vmax; |
| 16 | |
| 17 | if (argc < 4) { |
| 18 | log_err("%s: start end nvalues\n", argv[0]); |
| 19 | return 1; |
| 20 | } |
| 21 | |
| 22 | start = strtoul(argv[1], NULL, 10); |
| 23 | end = strtoul(argv[2], NULL, 10); |
| 24 | |
| 25 | if (start >= end) { |
| 26 | log_err("%s: start must be smaller than end\n", argv[0]); |
| 27 | return 1; |
| 28 | } |
| 29 | index = 1 + end - start; |
| 30 | buckets = calloc(index, sizeof(unsigned long)); |
| 31 | |
| 32 | nvalues = strtoul(argv[3], NULL, 10); |
| 33 | |
| 34 | init_rand(&s, false); |
| 35 | |
| 36 | for (i = 0; i < nvalues; i++) { |
| 37 | int v = rand_between(&s, start, end); |
| 38 | |
| 39 | buckets[v - start]++; |
| 40 | } |
| 41 | |
| 42 | p = 1.0 / index; |
| 43 | dev = sqrt(nvalues * p * (1.0 - p)); |
| 44 | mean = nvalues * p; |
| 45 | vmin = mean - dev; |
| 46 | vmax = mean + dev; |
| 47 | |
| 48 | pass = fail = 0; |
| 49 | for (i = 0; i < index; i++) { |
| 50 | if (buckets[i] < vmin || buckets[i] > vmax) { |
| 51 | printf("FAIL bucket%4lu: val=%8lu (%.1f < %.1f > %.1f)\n", (unsigned long) i + 1, buckets[i], vmin, mean, vmax); |
| 52 | fail++; |
| 53 | } else { |
| 54 | printf("PASS bucket%4lu: val=%8lu (%.1f < %.1f > %.1f)\n", (unsigned long) i + 1, buckets[i], vmin, mean, vmax); |
| 55 | pass++; |
| 56 | } |
| 57 | } |
| 58 | |
| 59 | printf("Passes=%lu, Fail=%lu\n", pass, fail); |
| 60 | free(buckets); |
| 61 | return 0; |
| 62 | } |