/***************************************************************************
 * Copyright (C) 1995, 1996, 1997  Jun Sun, jsun@junsun.net.               *
 *                                                                         *
 * This package contains a collection of distributions.  For each dist-    *
 * tribution there are desity function (mass function in discrete cases    *
 * distribution function  and random sample generator.                     *
 *                                                                         *
 ***************************************************************************
*/

#include "LCG.h"
#include <time.h>

static const unsigned long a = 314159269UL;
static const unsigned long c = 453806245UL;
static const unsigned long m = 2147483648UL;

LCG::LCG() { seed=time(0);} // determine the seed by the current time

LCG::LCG(long unsigned n) 
{ seed = n; }

void LCG::set_seed(long unsigned n) {seed = n; }

double LCG::sample()
{ seed = (seed*a + c) % m;
  if (seed==0) seed = c;

  return (double)seed / (double)m;
}