GSL bivariate

[genis]

Hi

I need to to use the function

void gsl_ran_bivariate_gaussian (const gsl rng * r, double sigma_x, double sigma_y, double rho, double * x, double * y )
But I get Segmation fault. I paste here my program

#include <iostream>
#include <cmath>
#include <gsl/gsl_randist.h>
#include <gsl/gsl_errno.h>
#include <gsl/gsl_cdf.h>



using namespace std;

int main (void){


double *x1,*x2;
double sigma1,sigma2,rho,area,c;
const gsl_rng * rtt;


sigma1=1.0;
sigma2=1.0;
rho=0.00001;

gsl_ran_bivariate_gaussian(rtt,sigma1,sigma2,rho,x1,x2);

cout<<*x1<<" "<<*x2<<endl;

return 0;

}

Thank you very much