X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fmath%2Finteraction.c;h=d24166d4379b18bf7e7b84c976b6cd4ad2aa4ad8;hb=2f15c0fb5c0c325c4ffa13240be41e533a82329d;hp=ff2c53571ac8bd79f79286cbfec054a992ece2b3;hpb=6fad5485ff9ba8e6decd8625cb79eb2910e934f2;p=pspp

diff --git a/src/math/interaction.c b/src/math/interaction.c
index ff2c53571a..d24166d437 100644
--- a/src/math/interaction.c
+++ b/src/math/interaction.c
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 2009 Free Software Foundation, Inc.
+   Copyright (C) 2011 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -14,121 +14,160 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 
+#include <config.h>
+
+#include "data/case.h"
+#include "interaction.h"
+
+#include "data/value.h"
+#include "data/variable.h"
+#include "libpspp/str.h"
+
+#include "gl/xalloc.h"
+
+#include <stdio.h>
+
+
 /*
-  An interaction is a gsl_vector containing a "product" of other
-  variables. The variables can be either categorical or numeric.
-  If the variables are all numeric, the interaction is just the
-  scalar product. If any of the variables are categorical, their
-  product is a vector containing 0's in all but one entry. This entry
-  is found by combining the vectors corresponding to the variables'
-  OBS_VALS member. If there are K categorical variables, each with
-  N_1, N_2, ..., N_K categories, then the interaction will have
-  N_1 * N_2 * N_3 *...* N_K - 1 entries.
-
-  When using these functions, make sure the orders of variables and
-  values match when appropriate.
- */
+  An interaction is a structure containing a "product" of other
+  variables. The variables can be either string or numeric.
 
-#include <config.h>
-#include <assert.h>
-#include <gsl/gsl_math.h>
-#include <gsl/gsl_vector.h>
-#include <data/value.h>
-#include <data/variable.h>
-#include <math/interaction.h>
-#include <string.h>
-#include <xalloc.h>
-
-struct interaction_variable
+  Interaction is commutative.  That means, that from a mathematical point of
+  view,  the order of the variables is irrelevant.  However, for display
+  purposes, and for matching with an interaction's value the order is 
+  pertinent.
+  
+  Therefore, when using these functions, make sure the orders of variables 
+  and values match when appropriate.
+*/
+
+
+
+struct interaction *
+interaction_create (const struct variable *v)
 {
-  int n_vars;
-  const struct variable **members;
-  struct variable *intr;
-};
+  struct interaction  *i = xmalloc (sizeof *i);
+  i->vars = xmalloc (sizeof *i->vars);
+  i->n_vars = 0;
+  if ( v )
+    {
+      i->vars[0] = v;
+      i->n_vars = 1;
+    }
+  return i;
+}
 
-struct interaction_value
+void
+interaction_destroy (struct interaction *i)
 {
-  const struct interaction_variable *intr;
-  union value *strings; /* Concatenation of the string values in this interaction's value. */
-  double f; /* Product of the numerical values in this interaction's value. */
-};
+  free (i->vars);
+  free (i);
+}
 
-struct interaction_variable *
-interaction_variable_create (const struct variable **vars, int n_vars)
+void
+interaction_add_variable (struct interaction *i, const struct variable *v)
 {
-  struct interaction_variable *result = NULL;
-  size_t i;
+  i->vars = xrealloc (i->vars, sizeof (*i->vars) * ++i->n_vars);
+  i->vars[i->n_vars - 1] = v;
+}
 
-  if (n_vars > 0)
+
+void
+interaction_dump (const struct interaction *i)
+{
+  int v = 0;
+  printf ("%s", var_get_name (i->vars[v]));
+  for (v = 1; v < i->n_vars; ++v)
     {
-      result = xmalloc (sizeof (*result));
-      result->members = xnmalloc (n_vars, sizeof (*result->members));
-      result->intr = var_create_internal (0);
-      result->n_vars = n_vars;
-      for (i = 0; i < n_vars; i++)
-	{
-	  result->members[i] = vars[i];
-	}
+      printf (" * %s", var_get_name (i->vars[v]));
     }
-  return result;
+  printf ("\n");
 }
 
-void interaction_variable_destroy (struct interaction_variable *iv)
+/* Appends STR with a representation of the interaction, suitable for user
+   display.
+
+   STR must have been initialised prior to calling this function.
+*/
+void
+interaction_to_string (const struct interaction *iact, struct string *str)
 {
-  var_destroy (iv->intr);
-  free (iv->members);
-  free (iv);
+  int v = 0;
+  ds_put_cstr (str, var_to_string (iact->vars[v]));
+  for (v = 1; v < iact->n_vars; ++v)
+    {
+      ds_put_cstr (str, " * ");
+      ds_put_cstr (str, var_to_string (iact->vars[v]));
+    }
 }
 
-size_t
-interaction_variable_get_n_vars (const struct interaction_variable *iv)
+unsigned int
+interaction_case_hash (const struct interaction *iact, const struct ccase *c)
 {
-  return (iv == NULL) ? 0 : iv->n_vars;
+  int i;
+  size_t hash = 0;
+  for (i = 0; i < iact->n_vars; ++i)
+    {
+      const struct variable *var = iact->vars[i];
+      const union value *val = case_data (c, var);
+      hash = value_hash (val, var_get_width (var), hash);
+    }
+  return hash;
 }
 
-/*
-  Given list of values, compute the value of the corresponding
-  interaction.  This "value" is not stored as the typical vector of
-  0's and one double, but rather the string values are concatenated to
-  make one big string value, and the numerical values are multiplied
-  together to give the non-zero entry of the corresponding vector.
- */
-struct interaction_value *
-interaction_value_create (const struct interaction_variable *var, const union value **vals)
+bool
+interaction_case_equal (const struct interaction *iact, const struct ccase *c1, const struct ccase *c2)
 {
-  struct interaction_value *result = NULL;
-  size_t i;
-  size_t n_vars;
-  
-  if (var != NULL)
+  int i;
+  bool same = true;
+
+  for (i = 0; i < iact->n_vars; ++i)
     {
-      result = xmalloc (sizeof (*result));
-      result->intr = var;
-      n_vars = interaction_variable_get_n_vars (var);
-      result->strings = value_create (n_vars * MAX_SHORT_STRING + 1);
-      result->f = 1.0;
-      for (i = 0; i < n_vars; i++)
+      const struct variable *var = iact->vars[i];
+      if ( ! value_equal (case_data (c1, var), case_data (c2, var), var_get_width (var)))
 	{
-	  if (var_is_alpha (var->members[i]))
-	    {
-	      strncat (result->strings->s, vals[i]->s, MAX_SHORT_STRING);
-	    }
-	  else if (var_is_numeric (var->members[i]))
-	    {
-	      result->f *= vals[i]->f;
-	    }
+	  same = false;
+	  break;
 	}
     }
+
+  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;
 }
 
-void 
-interaction_value_destroy (struct interaction_value *val)
+
+bool
+interaction_case_is_missing (const struct interaction *iact, const struct ccase *c, enum mv_class exclude)
 {
-  if (val != NULL)
+  int i;
+  bool missing = false;
+
+  for (i = 0; i < iact->n_vars; ++i)
     {
-      free (val->strings);
-      free (val);
+      if ( var_is_value_missing (iact->vars[i], case_data (c, iact->vars[i]), exclude))
+	{
+	  missing = true;
+	  break;
+	}
     }
+
+  return missing;
 }