source: cpp/gdk/rndutil.cpp @ 97

#include "rndutil.h"
#include "nonstd_math.h"
#include <stdlib.h>

unsigned short pseudornd(short x)
{
static long seed=0;
long y;
if (x<=0) {seed=-x; return 0;}
seed=(y=(3677*seed+3680)&0x7fffffff)-1;
return ((unsigned short)y)%(x);
}

double CustomRnd(double *tab)
{
double *range=tab+1+2*randomN((int)(0.5+tab[0]));
return range[0]+rnd0N(range[1]-range[0]);
};

double RandomGener::Uni(float begin, float end)
{
return begin+(double)rand()*(end-begin)/RAND_MAX;
}

double RandomGener::GaussStd()
{
if (isNextGauss) {isNextGauss=0; return nextGauss;}
double v1,v2,s;
do {
v1=2*rnd01-1; //-1..1
v2=2*rnd01-1; //-1..1
s=v1*v1+v2*v2;
} while (s>=1);
double mult=sqrt(-2*log(s)/s);
nextGauss=v2*mult;
isNextGauss=1;
return v1*mult;
}

double RandomGener::Gauss(float m,float s)
{return m+s*GaussStd();}

RandomGener RndGen;