src/math/mode.h

   1 /* PSPP - a program for statistical analysis.
   2    Copyright (C) 2004, 2008, 2009, 2022 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
  16
  17 #ifndef MATH_MODE_H
  18 #define MATH_MODE_H 1
  19
  20 #include <stddef.h>
  21
  22 #include "order-stats.h"
  23
  24 /* To calculate the mode:
  25
  26    - Create a "struct mode" with mode_create().
  27    - Feed in the data with order_stats_accumulate() or
  28      order_stats_accumulate_idx().  The data must be in sorted order: if
  29      necessary, use one of the sorting functions from sort.h to sort them.
  30    - The members of "struct mode" then designate the mode.
  31    - Destroy the data structure with statistic_destroy().
  32 */
  33
  34 struct mode
  35 {
  36   struct order_stats parent;
  37
  38   /* These are initialized by order_stats_accumulate{_idx}(). */
  39   double mode;          /* The value of the smallest mode, if 'n_modes' > 0. */
  40   double mode_weight;   /* The weight of each mode, if 'n_modes' > 0. */
  41   size_t n_modes;       /* The number of modes. */
  42 };
  43
  44 struct mode *mode_create (void);
  45
  46 #endif /* mode.h */