Rewrite PSPP output engine.

[pspp-builds.git] / src / language / stats / t-test.q

diff --git a/src/language/stats/t-test.q b/src/language/stats/t-test.q
index c448d52ea035c3d163bef9bf343a8d6b9609f904..8aee3b157992827fa9021c876b39822809ab43b2 100644 (file)
--- a/src/language/stats/t-test.q
+++ b/src/language/stats/t-test.q
@@ -43,8 +43,8 @@
 #include <libpspp/taint.h>
 #include <math/group-proc.h>
 #include <math/levene.h>
-#include <output/manager.h>
-#include <output/table.h>
+#include <math/correlation.h>
+#include <output/tab.h>
 #include <data/format.h>
 
 #include "minmax.h"
@@ -476,13 +476,11 @@ static void
 ssbox_base_init (struct ssbox *this, int cols, int rows)
 {
   this->finalize = ssbox_base_finalize;
-  this->t = tab_create (cols, rows, 0);
+  this->t = tab_create (cols, rows);
 
-  tab_columns (this->t, SOM_COL_DOWN, 1);
   tab_headers (this->t, 0, 0, 1, 0);
   tab_box (this->t, TAL_2, TAL_2, TAL_0, TAL_1, 0, 0, cols - 1, rows - 1);
   tab_hline (this->t, TAL_2, 0, cols- 1, 1);
-  tab_dim (this->t, tab_natural_dimensions, NULL);
 }
 \f
 /* ssbox implementations. */
@@ -1068,11 +1066,10 @@ trbox_base_init (struct trbox *self, size_t data_rows, int cols)
   const size_t rows = 3 + data_rows;
 
   self->finalize = trbox_base_finalize;
-  self->t = tab_create (cols, rows, 0);
+  self->t = tab_create (cols, rows);
   tab_headers (self->t, 0, 0, 3, 0);
   tab_box (self->t, TAL_2, TAL_2, TAL_0, TAL_0, 0, 0, cols - 1, rows - 1);
   tab_hline (self->t, TAL_2, 0, cols- 1, 3);
-  tab_dim (self->t, tab_natural_dimensions, NULL);
 }
 
 /* Base finalizer for the trbox */
@@ -1092,14 +1089,12 @@ pscbox (struct t_test_proc *proc)
 
   struct tab_table *table;
 
-  table = tab_create (cols, rows, 0);
+  table = tab_create (cols, rows);
 
-  tab_columns (table, SOM_COL_DOWN, 1);
   tab_headers (table, 0, 0, 1, 0);
   tab_box (table, TAL_2, TAL_2, TAL_0, TAL_1, 0, 0, cols - 1, rows - 1);
   tab_hline (table, TAL_2, 0, cols - 1, 1);
   tab_vline (table, TAL_2, 2, 0, rows - 1);
-  tab_dim (table, tab_natural_dimensions, NULL);
   tab_title (table, _("Paired Samples Correlations"));
 
   /* column headings */
@@ -1110,14 +1105,6 @@ pscbox (struct t_test_proc *proc)
   for (i = 0; i < proc->n_pairs; i++)
     {
       struct pair *pair = &proc->pairs[i];
-      double df = pair->n - 2;
-      double p, q;
-
-      /* corr2 will mathematically always be in the range [0, 1.0].  Inaccurate
-         calculations sometimes cause it to be slightly greater than 1.0, so
-         force it into the correct range to avoid NaN from sqrt(). */
-      double corr2 = MIN (1.0, pow2 (pair->correlation));
-      double correlation_t = pair->correlation * sqrt (df) / sqrt (1 - corr2);
 
       /* row headings */
       tab_text_format (table, 0, i + 1, TAB_LEFT | TAT_TITLE,
@@ -1131,10 +1118,8 @@ pscbox (struct t_test_proc *proc)
       tab_double (table, 2, i + 1, TAB_RIGHT, pair->n, &proc->weight_format);
       tab_double (table, 3, i + 1, TAB_RIGHT, pair->correlation, NULL);
 
-      p = gsl_cdf_tdist_P (correlation_t, df);
-      q = gsl_cdf_tdist_Q (correlation_t, df);
-      tab_double (table, 4, i + 1, TAB_RIGHT,
-                 2.0 * (correlation_t > 0 ? q : p), NULL);
+      tab_double (table, 4, i + 1, TAB_RIGHT, 
+                 2.0 * significance_of_correlation (pair->correlation, pair->n), NULL);
     }
 
   tab_submit (table);