From fce988c7764a1423b971e8c9075deca20d3874fe Mon Sep 17 00:00:00 2001 From: "osdl.net!shemminger" Date: Mon, 23 Aug 2004 20:21:21 +0000 Subject: [PATCH] Allow variable tablesize. 2004/08/10 10:46:00-07:00 osdl.net!shemminger Rename: tc/dist_normal.c -> tc/normal.c (Logical change 1.71) --- tc/normal.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) diff --git a/tc/normal.c b/tc/normal.c index e69de29b..8926b521 100644 --- a/tc/normal.c +++ b/tc/normal.c @@ -0,0 +1,58 @@ +/* + * Normal distribution table generator + * Taken from the uncopyrighted NISTnet code. + */ +#include +#include +#include +#include +#include + +#include +#include + +#define TABLESIZE 16384 +#define TABLEFACTOR TCA_NETEM_TABLEFACTOR + +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) +{ + double x, *table; + int i, n; + + table = calloc(sizeof(double), TABLESIZE); + if (!table) { + fprintf(stderr, "Not enough memory\n"); + return 1; + } + + + for (x = -10.0; x < 10.05; x += .00005) { + i = (int)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; + } + } + free(table); + return 0; +} -- 2.39.5