Avoid numerical problems with missing weights on non-linear cases.

[pspp] / src / math / order-stats.c

diff --git a/src/math/order-stats.c b/src/math/order-stats.c
index e550d2b2eb55f66fd4baea366e7a058abb849443..e8e078f4b6f066913d1081aadab2c7692886d19a 100644 (file)
--- a/src/math/order-stats.c
+++ b/src/math/order-stats.c
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 2008, 2009 Free Software Foundation, Inc.
+   Copyright (C) 2008, 2009, 2011 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
@@ -15,14 +15,18 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 
 #include <config.h>
-#include "order-stats.h"
-#include <libpspp/assertion.h>
-#include <data/val-type.h>
-#include <gl/xalloc.h>
-#include <data/variable.h>
-#include <data/casereader.h>
+
+#include "math/order-stats.h"
+
 #include <string.h>
 
+#include "data/casereader.h"
+#include "data/val-type.h"
+#include "data/variable.h"
+#include "libpspp/assertion.h"
+
+#include "gl/xalloc.h"
+
 #if 0
 
 #include <stdio.h>
@@ -58,7 +62,7 @@ static void
 update_k_lower (struct k *kk,
                double y_i, double c_i, double cc_i)
 {
-  if ( cc_i <= kk->tc )
+  if (cc_i <= kk->tc)
     {
       kk->cc = cc_i;
       kk->c = c_i;
@@ -71,7 +75,7 @@ static void
 update_k_upper (struct k *kk,
                double y_i, double c_i, double cc_i)
 {
-  if ( cc_i > kk->tc && kk->c_p1 == 0)
+  if (cc_i > kk->tc && kk->c_p1 == 0)
     {
       kk->cc_p1 = cc_i;
       kk->c_p1 = c_i;
@@ -98,7 +102,7 @@ update_k_values (const struct ccase *cx, double y_i, double c_i, double cc_i,
          update_k_upper (myk, y_i, c_i, cc_i);
        }
 
-      if ( stat->accumulate )
+      if (stat->accumulate)
        stat->accumulate (stat, cx, c_i, cc_i, y_i);
 
       tos->cc = cc_i;
@@ -107,11 +111,10 @@ update_k_values (const struct ccase *cx, double y_i, double c_i, double cc_i,
 
 
 void
-order_stats_accumulate (struct order_stats **os, size_t nos,
-                       struct casereader *reader,
-                       const struct variable *wv,
-                       const struct variable *var,
-                       enum mv_class exclude)
+order_stats_accumulate_idx (struct order_stats **os, size_t nos,
+                            struct casereader *reader,
+                            int wt_idx,
+                            int val_idx)
 {
   struct ccase *cx;
   struct ccase *prev_cx = NULL;
@@ -122,26 +125,25 @@ order_stats_accumulate (struct order_stats **os, size_t nos,
 
   for (; (cx = casereader_read (reader)) != NULL; case_unref (cx))
     {
-      const double weight = wv ? case_data (cx, wv)->f : 1.0;
-      const double this_value = case_data (cx, var)->f;
+      const double weight = wt_idx == -1 ? 1.0 : case_num_idx (cx, wt_idx);
+      const double this_value = case_num_idx (cx, val_idx);
+
+      if (weight == SYSMIS)
+        continue;
 
       /* The casereader MUST be sorted */
       assert (this_value >= prev_value);
 
-      if ( var_is_value_missing (var, case_data (cx, var), exclude))
-       continue;
-
-      case_unref (prev_cx);
-
-      if ( prev_value == -DBL_MAX || prev_value == this_value)
+      if (prev_value == -DBL_MAX || prev_value == this_value)
        c_i += weight;
 
-      if ( prev_value > -DBL_MAX && this_value > prev_value)
+      if (prev_value > -DBL_MAX && this_value > prev_value)
        {
          update_k_values (prev_cx, prev_value, c_i, cc_i, os, nos);
          c_i = weight;
        }
 
+      case_unref (prev_cx);
       cc_i += weight;
       prev_value = this_value;
       prev_cx = case_ref (cx);
@@ -154,4 +156,19 @@ order_stats_accumulate (struct order_stats **os, size_t nos,
 }
 
 
-
+void
+order_stats_accumulate (struct order_stats **os, size_t nos,
+                       struct casereader *reader,
+                       const struct variable *wv,
+                       const struct variable *var,
+                       enum mv_class exclude)
+{
+  /* Filter out missing cases */
+  reader = casereader_create_filter_missing (reader, &var, 1,
+                                             exclude, NULL, NULL);
+
+  order_stats_accumulate_idx (os, nos,
+                              reader,
+                              wv ? var_get_case_index (wv) : -1,
+                              var_get_case_index (var));
+}