Rename: tc/paretonormal.c -> netem/paretonormal.c

(Logical change 1.141)

diff --git a/netem/paretonormal.c b/netem/paretonormal.c
index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..c793df6d5f4316f27f85db13b74ba42939531e83 100644 (file)
--- a/netem/paretonormal.c
+++ b/netem/paretonormal.c
@@ -0,0 +1,90 @@
+/*
+ * Paretoormal distribution table generator
+ *
+ * This distribution is simply .25*normal + .75*pareto; a combination
+ * which seems to match experimentally observed distributions reasonably
+ *  well, but is computationally easy to handle.
+ * The entries represent a scaled inverse of the cumulative distribution
+ * function.
+ *
+ * Taken from the uncopyrighted NISTnet code.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <limits.h>
+#include <malloc.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));
+}
+
+
+static const double a=3.0;
+
+static int
+paretovalue(int i)
+{
+       double dvalue;
+
+       i = 65536-4*i;
+       dvalue = (double)i/(double)65536;
+       dvalue = 1.0/pow(dvalue, 1.0/a);
+       dvalue -= 1.5;
+       dvalue *= (4.0/3.0)*(double)TABLEFACTOR;
+       if (dvalue > 32767)
+               dvalue = 32767;
+       return (int)rint(dvalue);
+}      
+
+int
+main(int argc, char **argv)
+{
+       double x;
+       double *table;
+       int i,n;
+
+       table = calloc(TABLESIZE+1, sizeof(double));
+       if (!table) {
+               fprintf(stderr, "Out of memory!\n");
+               exit(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 paretonormal distribution.\n"
+       );
+
+       for (i = n = 0; i < TABLESIZE; i += 4) {
+               int normvalue, parvalue, value;
+
+               normvalue = (int) rint(table[i]*TABLEFACTOR);
+               parvalue = paretovalue(i);
+
+               value = (normvalue+3*parvalue)/4;
+               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;
+}