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/* SPDX-License-Identifier: NIST-PD */
/*
* Normal distribution table generator
* Taken from the uncopyrighted NISTnet code.
*/
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <limits.h>
#include <linux/types.h>
#include <linux/pkt_sched.h>
#define TABLESIZE 16384
#define TABLEFACTOR NETEM_DIST_SCALE
static double
normal(double x, double mu, double sigma)
{
return .5 + .5*erf((x-mu)/(sqrt(2.0)*sigma));
}
int
main(int argc, char **argv)
{
int i, n;
double x;
double table[TABLESIZE+1];
for (x = -10.0; x < 10.05; x += .00005) {
i = rint(TABLESIZE * normal(x, 0.0, 1.0));
table[i] = x;
}
printf("# This is the distribution table for the normal distribution.\n");
for (i = n = 0; i < TABLESIZE; i += 4) {
int value = (int) rint(table[i]*TABLEFACTOR);
if (value < SHRT_MIN) value = SHRT_MIN;
if (value > SHRT_MAX) value = SHRT_MAX;
printf(" %d", value);
if (++n == 8) {
putchar('\n');
n = 0;
}
}
return 0;
}
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