Random1.cpp

#include "Random1.h"
#include <cstdlib>
#include <cmath>

// the basic math functions should be in namespace
// std but aren't in VCPP6

#if !defined(_MSC_VER)
using namespace std;
#endif

double GetOneGaussianBySummation()
{
	double result=0;
	for (unsigned long j=0; j < 12; j++)
		result += rand()/static_cast<double>(RAND_MAX);

	result -= 6.0;
	return result;
}


double GetOneGaussianByBoxMuller()
{
	double result;

	double x;
	double y;

	double sizeSquared;
	do {
		x = 2.0*rand()/static_cast<double>(RAND_MAX)-1;
		y = 2.0*rand()/static_cast<double>(RAND_MAX)-1;
		sizeSquared = x*x + y*y;
	}
	while
		(sizeSquared >= 1.0);

	result = x*sqrt(-2*log(sizeSquared)/sizeSquared);

	return result;
}