1/*
2 * Normal distribution table generator
3 * Taken from the uncopyrighted NISTnet code.
4 */
5#include <stdio.h>
6#include <stdlib.h>
7#include <math.h>
8#include <string.h>
9#include <limits.h>
10
11#include <linux/types.h>
12#include <linux/pkt_sched.h>
13
14#define TABLESIZE 16384
15#define TABLEFACTOR NETEM_DIST_SCALE
16
17static double
18normal(double x, double mu, double sigma)
19{
20	return .5 + .5*erf((x-mu)/(sqrt(2.0)*sigma));
21}
22
23
24int
25main(int argc, char **argv)
26{
27	int i, n;
28	double x;
29	double table[TABLESIZE+1];
30
31	for (x = -10.0; x < 10.05; x += .00005) {
32		i = rint(TABLESIZE * normal(x, 0.0, 1.0));
33		table[i] = x;
34	}
35
36
37	printf("# This is the distribution table for the normal distribution.\n");
38	for (i = n = 0; i < TABLESIZE; i += 4) {
39		int value = (int) rint(table[i]*TABLEFACTOR);
40		if (value < SHRT_MIN) value = SHRT_MIN;
41		if (value > SHRT_MAX) value = SHRT_MAX;
42
43		printf(" %d", value);
44		if (++n == 8) {
45			putchar('\n');
46			n = 0;
47		}
48	}
49
50	return 0;
51}
52