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/* statistics/median_source.c
*
* Copyright (C) 1996, 1997, 1998, 1999, 2000 Jim Davies, Brian Gough
*
* 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 2 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,median_from_sorted_data) (const BASE sorted_data[],
const size_t stride,
const size_t n)
{
double median ;
const size_t lhs = (n - 1) / 2 ;
const size_t rhs = n / 2 ;
if (n == 0)
return 0.0 ;
if (lhs == rhs)
{
median = sorted_data[lhs * stride] ;
}
else
{
median = (sorted_data[lhs * stride] + sorted_data[rhs * stride])/2.0 ;
}
return median ;
}
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