From a3dd22c0ed3bcf0d3cf5cf3e009c215eeb35b567 Mon Sep 17 00:00:00 2001
From: John Darrington <john@darrington.wattle.id.au>
Date: Mon, 11 Jul 2011 16:47:18 +0200
Subject: [PATCH] Fix ssq for interactions

---
 src/language/stats/glm.c |  8 +++-----
 src/math/covariance.c    | 32 --------------------------------
 src/math/covariance.h    |  5 +----
 3 files changed, 4 insertions(+), 41 deletions(-)

diff --git a/src/language/stats/glm.c b/src/language/stats/glm.c
index 54e60c05f9..3194fd8178 100644
--- a/src/language/stats/glm.c
+++ b/src/language/stats/glm.c
@@ -329,9 +329,7 @@ get_ssq (struct covariance *cov, gsl_vector * ssq, const struct glm_spec *cmd)
   size_t j;
   size_t k;
   size_t *dropped = xcalloc (covariance_dim (cov), sizeof (*dropped));
-  const struct variable **vars = xcalloc (covariance_dim (cov), sizeof (*vars));
-
-  covariance_get_var_indices (cov, vars);
+  const struct categoricals *cats = covariance_get_categoricals (cov);
 
   for (k = 0; k < cmd->n_interactions; k++)
     {
@@ -341,7 +339,8 @@ get_ssq (struct covariance *cov, gsl_vector * ssq, const struct glm_spec *cmd)
       size_t n_dropped = 0;
       for (i = cmd->n_dep_vars; i < covariance_dim (cov); i++)
 	{
-	  if (vars[i] == cmd->interactions[k]->vars[0])
+	  if (categoricals_get_interaction_by_subscript (cats, i - cmd->n_dep_vars)
+	      == cmd->interactions[k])
 	    {
 	      assert (n_dropped < covariance_dim (cov));
 	      dropped[n_dropped++] = i;
@@ -375,7 +374,6 @@ get_ssq (struct covariance *cov, gsl_vector * ssq, const struct glm_spec *cmd)
     }
 
   free (dropped);
-  free (vars);
   gsl_matrix_free (cm);
 }
 
diff --git a/src/math/covariance.c b/src/math/covariance.c
index aed42436ba..5dc1782638 100644
--- a/src/math/covariance.c
+++ b/src/math/covariance.c
@@ -738,36 +738,4 @@ covariance_dim (const struct covariance * cov)
   return (cov->dim);
 }
 
-/*
-  Returns an array of variables corresponding to rows of the covariance matrix.
-  In other words, element i of the array is the variable corresponding to 
-  row (and column) i of the covariance matrix.
- */
-void
-covariance_get_var_indices (const struct covariance *cov, const struct variable **vars)
-{
-  int i;
-  for (i = 0; i < cov->n_vars; i++)
-    {
-      vars[i] = cov->vars[i];
-    }
-  for (i = cov->n_vars; i < cov->dim; i++)
-    {
-      vars[i] = categoricals_get_variable_by_subscript (cov->categoricals, i - cov->n_vars);
-    }
-}
 
-
-void
-covariance_get_interaction_indices (const struct covariance *cov, const struct interaction **iacts)
-{
-  int i;
-  for (i = 0; i < cov->n_vars; i++)
-    {
-      iacts[i] = cov->vars[i];
-    }
-  for (i = cov->n_vars; i < cov->dim; i++)
-    {
-      iacts[i] = categoricals_get_interaction_by_subscript (cov->categoricals, i - cov->n_vars);
-    }
-}
diff --git a/src/math/covariance.h b/src/math/covariance.h
index 87afd8b282..ed5b3ee734 100644
--- a/src/math/covariance.h
+++ b/src/math/covariance.h
@@ -47,9 +47,6 @@ void covariance_destroy (struct covariance *cov);
 const gsl_matrix *covariance_moments (const struct covariance *cov, int m);
 
 const struct categoricals * covariance_get_categoricals (const struct covariance *cov);
-struct interaction;
-void covariance_get_interaction_indices (const struct covariance *cov, const struct interaction **iacts);
-
-void covariance_get_var_indices (const struct covariance *cov, const struct variable **vars);
 size_t covariance_dim (const struct covariance * cov);
+
 #endif
-- 
2.30.2