/* statistics/gastwirth_source.c

 * 

 * Copyright (C) 2018 Patrick Alken

 * 

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 3 of the License, or (at

 * your option) any later version.

 * 

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 */

double

FUNCTION(gsl_stats,gastwirth_from_sorted_data) (const BASE sorted_data[],

                                                const size_t stride,

                                                const size_t n)

{

  if (n == 0)

    {

      return 0.0;

    }

  else

    {

      double a = FUNCTION(gsl_stats,quantile_from_sorted_data)(sorted_data, stride, n, 1.0 / 3.0);

      double b = FUNCTION(gsl_stats,median_from_sorted_data)(sorted_data, stride, n);

      double c = FUNCTION(gsl_stats,quantile_from_sorted_data)(sorted_data, stride, n, 2.0 / 3.0);

      double gastwirth = 0.3 * a + 0.4 * b + 0.3 * c;

      return gastwirth;

    }

}