X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fmath%2Finteraction.c;h=269aa7e9ad9af816a56b5c95d2fc4ce9ea90dbf7;hb=refs%2Fbuilds%2F20111129030502%2Fpspp;hp=aa24250007da27b09723f5ddc4f115419fb10db5;hpb=3a82e941418b74d8f270cf164291a3938fff61d5;p=pspp

diff --git a/src/math/interaction.c b/src/math/interaction.c
index aa24250007..269aa7e9ad 100644
--- a/src/math/interaction.c
+++ b/src/math/interaction.c
@@ -48,14 +48,21 @@ interaction_create (const struct variable *v)
 {
   struct interaction  *i = xmalloc (sizeof *i);
   i->vars = xmalloc (sizeof *i->vars);
-  i->vars[0] = v;
-  i->n_vars = 1;
+  i->n_vars = 0;
+  if ( v )
+    {
+      i->vars[0] = v;
+      i->n_vars = 1;
+    }
   return i;
 }
 
 void
 interaction_destroy (struct interaction *i)
 {
+  if (NULL == i)
+    return;
+
   free (i->vars);
   free (i);
 }
@@ -68,6 +75,56 @@ interaction_add_variable (struct interaction *i, const struct variable *v)
 }
 
 
+/*
+  Do the variables in X->VARS constitute a proper
+  subset of the variables in Y->VARS?
+ */
+bool
+interaction_is_proper_subset (const struct interaction *x, const struct interaction *y)
+{
+  if (x->n_vars >= y->n_vars)
+    return false;
+
+  return interaction_is_subset (x, y);
+}
+
+/*
+  Do the variables in X->VARS constitute a 
+  subset (proper or otherwise) of the variables in Y->VARS?
+ */
+bool
+interaction_is_subset (const struct interaction *x, const struct interaction *y)
+{
+  size_t i;
+  size_t j;
+  size_t n = 0;
+
+  /* By definition, a subset cannot have more members than its superset */
+  if (x->n_vars > y->n_vars)
+    return false;
+
+  /* Count the number of values which are members of both sets */
+  for (i = 0; i < x->n_vars; i++)
+    {
+      for (j = 0; j < y->n_vars; j++)
+	{
+	  if (x->vars [i] == y->vars [j])
+	    {
+	      n++;
+	    }
+	}
+    }
+
+  /* If ALL the members of X were also found in Y, then this must be a subset */    
+  if (n >= x->n_vars)
+    return true;
+
+  return false;
+}
+
+
+
+
 void
 interaction_dump (const struct interaction *i)
 {
@@ -98,10 +155,10 @@ interaction_to_string (const struct interaction *iact, struct string *str)
 }
 
 unsigned int
-interaction_case_hash (const struct interaction *iact, const struct ccase *c)
+interaction_case_hash (const struct interaction *iact, const struct ccase *c, unsigned int base)
 {
   int i;
-  size_t hash = 0;
+  size_t hash = base;
   for (i = 0; i < iact->n_vars; ++i)
     {
       const struct variable *var = iact->vars[i];
@@ -130,6 +187,25 @@ interaction_case_equal (const struct interaction *iact, const struct ccase *c1,
   return same;
 }
 
+
+int
+interaction_case_cmp_3way (const struct interaction *iact, const struct ccase *c1, const struct ccase *c2)
+{
+  int i;
+  int result = 0;
+
+  for (i = 0; i < iact->n_vars; ++i)
+    {
+      const struct variable *var = iact->vars[i];
+      result = value_compare_3way (case_data (c1, var), case_data (c2, var), var_get_width (var));
+      if (result != 0)
+	break;
+    }
+
+  return result;
+}
+
+
 bool
 interaction_case_is_missing (const struct interaction *iact, const struct ccase *c, enum mv_class exclude)
 {