Use significance_of_correlation function in t-test.

[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 c0a6f47715acf6d6b69aba0a820f37905572f376..8f23cefd4afa54c8be6cfebe7031128a913e3616 100644 (file)
--- a/src/language/stats/t-test.q
+++ b/src/language/stats/t-test.q
@@ -43,10 +43,12 @@
 #include <libpspp/taint.h>
 #include <math/group-proc.h>
 #include <math/levene.h>
+#include <math/correlation.h>
 #include <output/manager.h>
 #include <output/table.h>
 #include <data/format.h>
 
+#include "minmax.h"
 #include "xalloc.h"
 #include "xmemdup0.h"
 
@@ -506,7 +508,7 @@ ssbox_one_sample_init (struct ssbox *this, struct t_test_proc *proc)
   tab_text (this->t, 1, 0, TAB_CENTER | TAT_TITLE, _("N"));
   tab_text (this->t, 2, 0, TAB_CENTER | TAT_TITLE, _("Mean"));
   tab_text (this->t, 3, 0, TAB_CENTER | TAT_TITLE, _("Std. Deviation"));
-  tab_text (this->t, 4, 0, TAB_CENTER | TAT_TITLE, _("SE. Mean"));
+  tab_text (this->t, 4, 0, TAB_CENTER | TAT_TITLE, _("S.E. Mean"));
 }
 
 /* Initialize the independent samples ssbox */
@@ -526,7 +528,7 @@ ssbox_independent_samples_init (struct ssbox *this, struct t_test_proc *proc)
   tab_text (this->t, 2, 0, TAB_CENTER | TAT_TITLE, _("N"));
   tab_text (this->t, 3, 0, TAB_CENTER | TAT_TITLE, _("Mean"));
   tab_text (this->t, 4, 0, TAB_CENTER | TAT_TITLE, _("Std. Deviation"));
-  tab_text (this->t, 5, 0, TAB_CENTER | TAT_TITLE, _("SE. Mean"));
+  tab_text (this->t, 5, 0, TAB_CENTER | TAT_TITLE, _("S.E. Mean"));
 }
 
 /* Populate the ssbox for independent samples */
@@ -577,10 +579,10 @@ ssbox_independent_samples_populate (struct ssbox *ssb,
 
       tab_text (ssb->t, 0, i * 2 + 1, TAB_LEFT,
                 var_get_name (proc->vars[i]));
-      tab_text (ssb->t, 1, i * 2 + 1, TAB_LEFT | TAT_PRINTF,
-                "%s%s", prefix[0], val_lab[0]);
-      tab_text (ssb->t, 1, i * 2 + 1+ 1, TAB_LEFT | TAT_PRINTF,
-                "%s%s", prefix[1], val_lab[1]);
+      tab_text_format (ssb->t, 1, i * 2 + 1, TAB_LEFT,
+                       "%s%s", prefix[0], val_lab[0]);
+      tab_text_format (ssb->t, 1, i * 2 + 1+ 1, TAB_LEFT,
+                       "%s%s", prefix[1], val_lab[1]);
 
       /* Fill in the group statistics */
       for (count = 0; count < 2; count++)
@@ -625,7 +627,7 @@ ssbox_paired_init (struct ssbox *this, struct t_test_proc *proc)
   tab_text (this->t, 2, 0, TAB_CENTER | TAT_TITLE, _("Mean"));
   tab_text (this->t, 3, 0, TAB_CENTER | TAT_TITLE, _("N"));
   tab_text (this->t, 4, 0, TAB_CENTER | TAT_TITLE, _("Std. Deviation"));
-  tab_text (this->t, 5, 0, TAB_CENTER | TAT_TITLE, _("SE. Mean"));
+  tab_text (this->t, 5, 0, TAB_CENTER | TAT_TITLE, _("S.E. Mean"));
 }
 
 /* Populate the ssbox for paired values */
@@ -639,7 +641,7 @@ ssbox_paired_populate (struct ssbox *ssb, struct t_test_proc *proc)
       struct pair *p = &proc->pairs[i];
       int j;
 
-      tab_text (ssb->t, 0, i * 2 + 1, TAB_LEFT | TAT_PRINTF, _("Pair %d"), i);
+      tab_text_format (ssb->t, 0, i * 2 + 1, TAB_LEFT, _("Pair %d"), i);
       for (j=0; j < 2; j++)
        {
          /* Titles */
@@ -757,9 +759,9 @@ trbox_independent_samples_init (struct trbox *self,
   tab_text (self->t, 9, 2, TAB_CENTER | TAT_TITLE, _("Lower"));
   tab_text (self->t, 10, 2, TAB_CENTER | TAT_TITLE, _("Upper"));
 
-  tab_joint_text (self->t, 9, 1, 10, 1, TAB_CENTER | TAT_PRINTF,
-                  _("%g%% Confidence Interval of the Difference"),
-                  proc->criteria * 100.0);
+  tab_joint_text_format (self->t, 9, 1, 10, 1, TAB_CENTER,
+                         _("%g%% Confidence Interval of the Difference"),
+                         proc->criteria * 100.0);
 }
 
 /* Populate the independent samples trbox */
@@ -911,9 +913,9 @@ trbox_paired_init (struct trbox *self, struct t_test_proc *proc)
   tab_hline (self->t, TAL_1, 5, 6, 2);
   tab_vline (self->t, TAL_GAP, 6, 0, 1);
 
-  tab_joint_text (self->t, 5, 1, 6, 1, TAB_CENTER | TAT_PRINTF,
-                  _("%g%% Confidence Interval of the Difference"),
-                  proc->criteria*100.0);
+  tab_joint_text_format (self->t, 5, 1, 6, 1, TAB_CENTER,
+                         _("%g%% Confidence Interval of the Difference"),
+                         proc->criteria*100.0);
 
   tab_text (self->t, 2, 2, TAB_CENTER | TAT_TITLE, _("Mean"));
   tab_text (self->t, 3, 2, TAB_CENTER | TAT_TITLE, _("Std. Deviation"));
@@ -942,10 +944,10 @@ trbox_paired_populate (struct trbox *trb,
       double t;
       double df = n - 1;
 
-      tab_text (trb->t, 0, i + 3, TAB_LEFT | TAT_PRINTF, _("Pair %d"), i);
-      tab_text (trb->t, 1, i + 3, TAB_LEFT | TAT_PRINTF, "%s - %s",
-               var_get_name (pair->v[0]),
-                var_get_name (pair->v[1]));
+      tab_text_format (trb->t, 0, i + 3, TAB_LEFT, _("Pair %d"), i);
+      tab_text_format (trb->t, 1, i + 3, TAB_LEFT, "%s - %s",
+                       var_get_name (pair->v[0]),
+                       var_get_name (pair->v[1]));
       tab_double (trb->t, 2, i + 3, TAB_RIGHT, pair->mean_diff, NULL);
       tab_double (trb->t, 3, i + 3, TAB_RIGHT, pair->std_dev_diff, NULL);
 
@@ -974,8 +976,8 @@ trbox_paired_populate (struct trbox *trb,
       /* Degrees of freedom */
       tab_double (trb->t, 8, i + 3, TAB_RIGHT, df, &proc->weight_format);
 
-      p = gsl_cdf_tdist_P (t, df);
-      q = gsl_cdf_tdist_P (t, df);
+      p = gsl_cdf_tdist_P (t,df);
+      q = gsl_cdf_tdist_Q (t,df);
 
       tab_double (trb->t, 9, i + 3, TAB_RIGHT, 2.0 * (t > 0 ? q : p), NULL);
     }
@@ -995,15 +997,15 @@ trbox_one_sample_init (struct trbox *self, struct t_test_proc *proc)
   tab_hline (self->t, TAL_1, 1, hsize - 1, 1);
   tab_vline (self->t, TAL_2, 1, 0, vsize - 1);
 
-  tab_joint_text (self->t, 1, 0, hsize - 1, 0, TAB_CENTER | TAT_PRINTF,
-                  _("Test Value = %f"), proc->testval);
+  tab_joint_text_format (self->t, 1, 0, hsize - 1, 0, TAB_CENTER,
+                         _("Test Value = %f"), proc->testval);
 
   tab_box (self->t, -1, -1, -1, TAL_1, 1, 1, hsize - 1, vsize - 1);
 
 
-  tab_joint_text (self->t, 5, 1, 6, 1, TAB_CENTER  | TAT_PRINTF,
-                  _("%g%% Confidence Interval of the Difference"),
-                  proc->criteria * 100.0);
+  tab_joint_text_format (self->t, 5, 1, 6, 1, TAB_CENTER,
+                         _("%g%% Confidence Interval of the Difference"),
+                         proc->criteria * 100.0);
 
   tab_vline (self->t, TAL_GAP, 6, 1, 1);
   tab_hline (self->t, TAL_1, 5, 6, 2);
@@ -1109,27 +1111,21 @@ pscbox (struct t_test_proc *proc)
   for (i = 0; i < proc->n_pairs; i++)
     {
       struct pair *pair = &proc->pairs[i];
-      double p, q;
-      double df = pair->n -2;
-      double correlation_t = (pair->correlation * sqrt (df) /
-                              sqrt (1 - pow2 (pair->correlation)));
 
       /* row headings */
-      tab_text (table, 0, i + 1, TAB_LEFT | TAT_TITLE | TAT_PRINTF,
-                _("Pair %d"), i);
-      tab_text (table, 1, i + 1, TAB_LEFT | TAT_TITLE | TAT_PRINTF,
-                _("%s & %s"),
-                var_get_name (pair->v[0]),
-                var_get_name (pair->v[1]));
+      tab_text_format (table, 0, i + 1, TAB_LEFT | TAT_TITLE,
+                       _("Pair %d"), i);
+      tab_text_format (table, 1, i + 1, TAB_LEFT | TAT_TITLE,
+                       _("%s & %s"),
+                       var_get_name (pair->v[0]),
+                       var_get_name (pair->v[1]));
 
       /* row data */
       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);