Fixed updating of covariance matrix when both variables

are categorical. Reported by John Darrington

diff --git a/src/data/category.c b/src/data/category.c
index 33078ce2b45528c1cd518e89fb7c798ae44334b6..1620bc7f7f9b3c27bbde71737eeb860d5c4f7cf0 100644 (file)
--- a/src/data/category.c
+++ b/src/data/category.c
@@ -148,6 +148,23 @@ cat_value_update (const struct variable *v, const union value *val)
        }
     }
 }
+/*
+  Return the count for the sth category.
+ */
+size_t
+cat_get_category_count (const size_t s, const struct variable *v)
+{
+  struct cat_vals *tmp;
+  size_t n_categories;
+
+  tmp = var_get_obs_vals (v);
+  n_categories = cat_get_n_categories (v);
+  if (s < n_categories)
+    {
+      return tmp->value_counts[s];
+    }
+  return CAT_VALUE_NOT_FOUND;
+}
 
 const union value *
 cat_subscript_to_value (const size_t s, const struct variable *v)

diff --git a/src/data/category.h b/src/data/category.h
index 6ef408577913207654bc77e5222edcd1e4fe7812..db4bb339bcb5e6ecab1bd0de98a76632dfe20f95 100644 (file)
--- a/src/data/category.h
+++ b/src/data/category.h
@@ -50,6 +50,11 @@ const union value *cat_subscript_to_value (const size_t,
 
 void cat_value_update (const struct variable *, const union value *);
 
+/*
+  Return the count for the sth category.
+*/
+size_t
+cat_get_category_count (const size_t, const struct variable *);
 
 /*
   Return the number of categories of a categorical variable.

diff --git a/src/math/covariance-matrix.c b/src/math/covariance-matrix.c
index 85998dfe49d80e1e20081f2bb503ce15bfc230e9..69aaf533a06afe9f584e32e2871784ecd8912c3b 100644 (file)
--- a/src/math/covariance-matrix.c
+++ b/src/math/covariance-matrix.c
@@ -69,13 +69,35 @@ covariance_update_categorical_numeric (struct design_matrix *cov, double mean,
       gsl_matrix_set (cov->m, row, col, (val2->f - mean) * x * weight);
     }
 }
+static void
+column_iterate (struct design_matrix *cov, const struct variable *v, double weight,
+               double ssize, double x, const union value *val1, size_t row)
+{
+  size_t col;
+  size_t i;
+  double y;
+  union value *tmp_val;
 
+  col = design_matrix_var_to_column (cov, v);  
+  for (i = 0; i < cat_get_n_categories (v) - 1; i++)
+    {
+      col += i;
+      y = -1.0 * cat_get_category_count (i, v) / ssize;
+      tmp_val = cat_subscript_to_value (i, v);
+      if (compare_values (tmp_val, val1, var_get_width (v)))
+       {
+         y += -1.0;
+       }
+      gsl_matrix_set (cov->m, row, col, x * y * weight);
+      gsl_matrix_set (cov->m, col, row, x * y * weight);
+    }
+}
 /*
-  Call this function in the first data pass. The central moments are
+  Call this function in the second data pass. The central moments are
   MEAN1 and MEAN2. Any categorical variables should already have their
   values summarized in in its OBS_VALS element.
  */
-void covariance_pass_one (struct design_matrix *cov, double mean1, double mean2,
+void covariance_pass_two (struct design_matrix *cov, double mean1, double mean2,
                          double weight, double ssize, const struct variable *v1, 
                          const struct variable *v2, const union value *val1, const union value *val2)
 {
@@ -83,7 +105,7 @@ void covariance_pass_one (struct design_matrix *cov, double mean1, double mean2,
   size_t col;
   size_t i;
   double x;
-  double y;
+  union value *tmp_val;
 
   if (var_is_alpha (v1))
     {
@@ -94,18 +116,18 @@ void covariance_pass_one (struct design_matrix *cov, double mean1, double mean2,
        }
       else
        {
-         row = design_matrix_var_to_column (cov, v1);  
-         col = design_matrix_var_to_column (cov, v2);
-         for (i = 0; i < cat_get_n_categories (v2); i++)
+         row = design_matrix_var_to_column (cov, v1);
+         for (i = 0; i < cat_get_n_categories (v1) - 1; i++)
            {
-             col += i;
-             y = -1.0 * cat_get_n_categories (v2) / ssize;
-             if (i == cat_value_find (v2, val2))
+             row += i;
+             x = -1.0 * cat_get_category_count (i, v1) / ssize;
+             tmp_val = cat_subscript_to_value (i, v1);
+             if (compare_values (tmp_val, val1, var_get_width (v1)))
                {
-                 y += 1.0;
+                 x += 1.0;
                }
-             gsl_matrix_set (cov->m, row, col, x * y * weight);
-             gsl_matrix_set (cov->m, col, row, x * y * weight);
+             column_iterate (cov, v1, weight, ssize, x, val1, row);
+             column_iterate (cov, v2, weight, ssize, x, val2, row);
            }
        }
     }