math: Avoid unneeded extra allocations for fixed-size data structures.

[pspp] / src / math / percentiles.h

diff --git a/src/math/percentiles.h b/src/math/percentiles.h
index 8f4271f56753a8e7c7e047df04958ff30eed9faa..86fd641addd46d5e6c3c955e547421a04649cf65 100644 (file)
--- a/src/math/percentiles.h
+++ b/src/math/percentiles.h
@@ -1,83 +1,62 @@
-/* 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.
-Author: John Darrington 2004
+   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 "hash.h"
-
-struct weighted_value ;
+#include "order-stats.h"
 
 /* The algorithm used to calculate percentiles */
 enum pc_alg {
-  PC_NONE=0, 
-  PC_HAVERAGE, 
-  PC_WAVERAGE, 
-  PC_ROUND, 
-  PC_EMPIRICAL, 
+  PC_NONE=0,
+  PC_HAVERAGE,
+  PC_WAVERAGE,
+  PC_ROUND,
+  PC_EMPIRICAL,
   PC_AEMPIRICAL
 } ;
 
+struct percentile
+{
+  struct order_stats parent;
 
+  double ptile;
+  double w;
 
-extern  const char *ptile_alg_desc[];
-
-
-
-
-struct percentile {
+  /* Mutable */
+  double g1;
+  double g1_star;
 
-  /* The break point of the percentile */
-  double p;
+  double g2;
+  double g2_star;
 
-  /* The value of the percentile */
-  double v;
+  struct k k[2];
 };
 
-
-/* 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.
+/* Create the Pth percentile.
+   W is the total sum of weights in 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]);
-
-
+struct percentile *percentile_create (double p, double W);
 
-/* Hash utility functions */
-int ptile_compare(const struct percentile *p1, 
-                  const struct percentile *p2, 
-                  void *aux);
+/* Return the value of the percentile */
+double percentile_calculate (const struct percentile *ptl, enum pc_alg alg);
 
-unsigned ptile_hash(const struct percentile *p, void *aux);
+void percentile_dump (const struct percentile *ptl);
 
 
 #endif