#include "gen_norm.h"
#include <stdio.h>
#include <assert.h>
#include <math.h>
#include <time.h>
#include <unistd.h>	/* used for getpid to initialize random */

void test_norm(int c)
{
    int i;
    clock_t start_time,     stop_time;
    
    double x;
    double sum=0, sum2=0, count=0;
    double var;
    
    start_time = clock();
    
    for (i=0; i<c; i++)
    {   x = gen_norm();
	sum += x;
	sum2+= x*x;
	count ++;
    }
    stop_time = clock();
    
    var = (count*sum2-sum*sum)/(count*(count-1));
    
    printf("For standard normal, sample of %g, %g microseconds/sample\n",
    	count, (stop_time-start_time+0.0)/count);
    printf("mean= %g, std dev=%g\n", sum/count, sqrt(var));
    printf("\n");
}


main()
{
    srandom(getpid());
    test_norm(2000000);
}