CROSSTABS: Calculate ASE for asymmetric lambda (correctly).

[pspp] / src / language / stats / crosstabs.q

diff --git a/src/language/stats/crosstabs.q b/src/language/stats/crosstabs.q
index e3f5aee1d573ec8dc105d085538cc677090fcd26..be22e62600c0bb72c21fbba98204196f00e6963d 100644 (file)
--- a/src/language/stats/crosstabs.q
+++ b/src/language/stats/crosstabs.q
@@ -17,10 +17,9 @@
 /* FIXME:
 
    - How to calculate significance of symmetric and directional measures?
-   - How to calculate ASE for asymmetric lambda?
-   - How to calculate ASE for symmetric Somers' d?
+   - How to calculate ASE for symmetric Somers ' d?
    - How to calculate ASE for Goodman and Kruskal's tau?
-   - Approx. T of uncertainty coefficient is wrong.
+   - How to calculate approx. T of symmetric uncertainty coefficient?
 
 */
 
@@ -2800,8 +2799,17 @@ calc_directional (struct crosstabs_proc *proc, struct pivot_table *pt,
       v[1] = (sum_fmj - rm) / (pt->total - rm);
       v[2] = (sum_fim - cm) / (pt->total - cm);
 
-      /* XXX We don't have a working formula for ASE1. */
-      ase[2] = SYSMIS;
+      /* ASE1 for Y given PT. */
+      {
+        double accum;
+
+        accum = 0.;
+       for (i = 0; i < pt->n_rows; i++)
+          if (cm_index == fim_index[i])
+            accum += fim[i];
+        ase[2] = sqrt ((pt->total - sum_fim) * (sum_fim + cm - 2. * accum)
+                       / pow3 (pt->total - cm));
+      }
 
       /* ASE0 for Y given PT. */
       {
@@ -2814,8 +2822,17 @@ calc_directional (struct crosstabs_proc *proc, struct pivot_table *pt,
        t[2] = v[2] / (sqrt (accum - pow2 (sum_fim - cm) / pt->total) / (pt->total - cm));
       }
 
-      /* XXX We don't have a working formula for ASE1. */
-      ase[1] = SYSMIS;
+      /* ASE1 for PT given Y. */
+      {
+        double accum;
+
+        accum = 0.;
+       for (j = 0; j < pt->n_cols; j++)
+          if (rm_index == fmj_index[j])
+            accum += fmj[j];
+        ase[1] = sqrt ((pt->total - sum_fmj) * (sum_fmj + rm - 2. * accum)
+                       / pow3 (pt->total - rm));
+      }
 
       /* ASE0 for PT given Y. */
       {
@@ -2920,8 +2937,7 @@ calc_directional (struct crosstabs_proc *proc, struct pivot_table *pt,
 
       v[5] = 2. * ((UX + UY - UXY) / (UX + UY));
       ase[5] = (2. / (pt->total * pow2 (UX + UY))) * sqrt (ase1_sym);
-      t[5] = v[5] / ((2. / (pt->total * (UX + UY)))
-                    * sqrt (P - pow2 (UX + UY - UXY) / pt->total));
+      t[5] = SYSMIS;
 
       v[6] = (UX + UY - UXY) / UX;
       ase[6] = sqrt (ase1_xy) / (pt->total * UX * UX);