Kruskal-Wallis: Sort grouped ranks before displaying them.

Debian's autobuilder showed that the KW tests were failing because the
hash which holds the rank entries was being iterated in arbitrary order.
This change sorts the entries before displaying them, so they should
always appear in the same order.

diff --git a/src/language/stats/kruskal-wallis.c b/src/language/stats/kruskal-wallis.c
index ecab0348d1ae16986f85e905ed19e0bd43fe4d50..cea302bcb9f29db66f6becedb028ec328edd2af8 100644 (file)
--- a/src/language/stats/kruskal-wallis.c
+++ b/src/language/stats/kruskal-wallis.c
@@ -31,6 +31,7 @@
 #include "data/variable.h"
 #include "libpspp/assertion.h"
 #include "libpspp/hmap.h"
+#include "libpspp/bt.h"
 #include "libpspp/message.h"
 #include "libpspp/misc.h"
 #include "math/sort.h"
@@ -59,12 +60,27 @@ include_func (const struct ccase *c, void *aux)
 struct rank_entry
 {
   struct hmap_node node;
+  struct bt_node btn;
   union value group;
 
   double sum_of_ranks;
   double n;
 };
 
+
+static int
+compare_rank_entries_3way (const struct bt_node *a,
+                           const struct bt_node *b,
+                           const void *aux)
+{
+  const struct variable *var = aux;
+  const struct rank_entry *rea = bt_data (a, struct rank_entry, btn);
+  const struct rank_entry *reb = bt_data (b, struct rank_entry, btn);
+
+  return value_compare_3way (&rea->group, &reb->group, var_get_width (var));
+}
+
+
 /* Return the entry with the key GROUP or null if there is no such entry */
 static struct rank_entry *
 find_rank_entry (const struct hmap *map, const union value *group, size_t width)
@@ -264,7 +280,9 @@ show_ranks_box (const struct n_sample_test *nst, const struct kw *kw, int n_grou
   for (i = 0 ; i < nst->n_vars ; ++i)
     {
       int tot = 0;
-      const struct rank_entry *re;
+      struct rank_entry *re_x;
+      struct bt_node *bt_n = NULL;
+      struct bt bt;
 
       if (i > 0)
        tab_hline (table, TAL_1, 0, tab_nc (table) -1, row);
@@ -272,21 +290,36 @@ show_ranks_box (const struct n_sample_test *nst, const struct kw *kw, int n_grou
       tab_text (table,  0, row,
                TAT_TITLE, var_to_string (nst->vars[i]));
 
-      HMAP_FOR_EACH (re, const struct rank_entry, node, &kw[i].map)
+      /* Sort the rank entries, by iteratin the hash and putting the entries
+         into a binary tree. */
+      bt_init (&bt, compare_rank_entries_3way, nst->vars[i]);
+      HMAP_FOR_EACH (re_x, struct rank_entry, node, &kw[i].map)
        {
+          bt_insert (&bt, &re_x->btn);
+        }
+
+      /* Report the rank entries in sorted order. */
+      for (bt_n = bt_first (&bt);
+           bt_n != NULL;
+           bt_n = bt_next (&bt, bt_n) )
+        {
+          const struct rank_entry *re =
+            bt_data (bt_n, const struct rank_entry, btn);
+
          struct string str;
          ds_init_empty (&str);
-
+          
          var_append_value_name (nst->indep_var, &re->group, &str);
-
+          
          tab_text   (table, 1, row, TAB_LEFT, ds_cstr (&str));
          tab_double (table, 2, row, TAB_LEFT, re->n, &F_8_0);
          tab_double (table, 3, row, TAB_LEFT, re->sum_of_ranks / re->n, 0);
-
+          
          tot += re->n;
          row++;
          ds_destroy (&str);
        }
+
       tab_double (table, 2, row, TAB_LEFT,
                  tot, &F_8_0);
       tab_text (table, 1, row++, TAB_LEFT, _("Total"));

diff --git a/tests/language/stats/npar.at b/tests/language/stats/npar.at
index 4fa26ecf4749fd71febeff6c63f6cc27ca0d9fa3..874e83de810ae99ac826964105f97917a3d5235d 100644 (file)
--- a/tests/language/stats/npar.at
+++ b/tests/language/stats/npar.at
@@ -672,8 +672,8 @@ AT_CHECK([cat pspp.csv], [0], [dnl
 Table: Ranks
 ,gv,N,Mean Rank
 xscore,timed out,5,4.400
-,handled the ball,4,11.500
 ,hit wicket,5,7.400
+,handled the ball,4,11.500
 ,Total,14,
 
 Table: Test Statistics
@@ -776,12 +776,12 @@ AT_CHECK([cat pspp.csv], [0], [dnl
 Table: Ranks
 ,gv,N,Mean Rank
 xscore,timed out,5,4.400
-,handled the ball,4,11.500
 ,hit wicket,5,7.400
+,handled the ball,4,11.500
 ,Total,14,
-yscore,handled the ball,4,11.500
+yscore,hit wicket,5,7.400
+,handled the ball,4,11.500
 ,bowled,5,4.400
-,hit wicket,5,7.400
 ,Total,14,
 
 Table: Test Statistics