#include <stdio.h>

#include <gsl/gsl_sort.h>

#include <gsl/gsl_statistics.h>

int

main(void)

{

  double data[5] = {17.2, 18.1, 16.5, 18.3, 12.6};

  double median, upperq, lowerq;

  printf ("Original dataset:  %g, %g, %g, %g, %g\n",

         data[0], data[1], data[2], data[3], data[4]);

  gsl_sort (data, 1, 5);

  printf ("Sorted dataset: %g, %g, %g, %g, %g\n",

         data[0], data[1], data[2], data[3], data[4]);

  median 

    = gsl_stats_median_from_sorted_data (data, 

                                         1, 5);

  upperq 

    = gsl_stats_quantile_from_sorted_data (data, 

                                           1, 5,

                                           0.75);

  lowerq 

    = gsl_stats_quantile_from_sorted_data (data, 

                                           1, 5,

                                           0.25);

  printf ("The median is %g\n", median);

  printf ("The upper quartile is %g\n", upperq);

  printf ("The lower quartile is %g\n", lowerq);

  return 0;

}