#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <sys/time.h>

#include "mersenne.h"

/* Generates random numbers from Gaussian distribution.
 * Compile: 
 * cc -o grnd_generate grnd_generate.c gaussian_ran.c mersenne_inline.c -lm
 */

char usage[]  = " usage: grnd_generate N \n\
  Generates N gaussian random numbers\n";

double gaussian_ran(void);            /* Prototype for the function! */

int main(int argc,char *argv[])
{
  struct timeval tv;
  struct timezone tz;
  double res,err;
  int loops,n,i;

  /* require correct number of arguments 
   */
  if (argc != 2) {
    fprintf(stderr,usage);
    exit(0);
  }

  n = atoi(argv[1]);    /* first int */
  
  /* seed the random number using system time
   * tv.tv_sec contains time in seconds, tv.tv_usec in microseconds
   */

  gettimeofday( &tv, &tz );
  seed_mersenne( tv.tv_sec + tv.tv_usec );

  for (i=0; i<100000; i++) mersenne();  

  for (i=0; i<n; i++) {
    printf("%.12g\n", gaussian_ran() );
  }
 
  return(1);
}