-/* PSPP - A program for statistical analysis . -*-c-*-
+/* PSPP - a program for statistical analysis.
+ Copyright (C) 2004, 2008, 2009 Free Software Foundation, Inc.
-Copyright (C) 2004 Free Software Foundation, Inc.
+ 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 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.
-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, see <http://www.gnu.org/licenses/>. */
-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. */
+#ifndef __PERCENTILES_H__
+#define __PERCENTILES_H__
-#ifndef PERCENTILES_H
-#define PERCENTILES_H
+#include <stddef.h>
+#include "order-stats.h"
-#include <libpspp/hash.h>
+/* To calculate a percentile:
-struct weighted_value ;
+ - Create a "struct percentile" with percentile_create().
+ - Feed in the data with order_stats_accumulate() or
+ order_stats_accumulate_idx(). The data must be in sorted order: if
+ necessary, use one of the sorting functions from sort.h to sort them.
+ - Obtain the percentile with percentile_calculate().
+ - Destroy the data structure with statistic_destroy().
+*/
/* The algorithm used to calculate percentiles */
enum pc_alg {
PC_AEMPIRICAL
} ;
+struct percentile
+{
+ struct order_stats parent;
+ double ptile;
+ double w;
-extern const char *const ptile_alg_desc[];
-
-
-
+ /* Mutable */
+ double g1;
+ double g1_star;
-struct percentile {
+ double g2;
+ double g2_star;
- /* The break point of the percentile */
- double p;
-
- /* The value of the percentile */
- double v;
+ struct k k[2];
};
+struct percentile *percentile_create (double p, double W);
+double percentile_calculate (const struct percentile *, enum pc_alg);
-/* Calculate the percentiles of the break points in pc_bp,
- placing the values in pc_val.
- wv is a sorted array of weighted values of the data set.
-*/
-void ptiles(struct hsh_table *pc_hash,
- const struct weighted_value **wv,
- int n_data,
- double w,
- enum pc_alg algorithm);
-
-
-/* Calculate Tukey's Hinges and the Whiskers for the box plot*/
-void tukey_hinges(const struct weighted_value **wv,
- int n_data,
- double w,
- double hinges[3]);
-
-
-
-/* Hash utility functions */
-int ptile_compare(const struct percentile *p1,
- const struct percentile *p2,
- void *aux);
-
-unsigned ptile_hash(const struct percentile *p, void *aux);
-
-
-#endif
+#endif /* percentiles.h */