X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fmath%2Fcategoricals.c;h=83326c3f006789814c4930feed8d85d15db95155;hb=b9f712f8911170fcc049c6d7d83b6887185de4dd;hp=f1bd09023758c0777507ca752b7b8462c23d5ea1;hpb=2f15c0fb5c0c325c4ffa13240be41e533a82329d;p=pspp

diff --git a/src/math/categoricals.c b/src/math/categoricals.c
index f1bd090237..83326c3f00 100644
--- a/src/math/categoricals.c
+++ b/src/math/categoricals.c
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 2009, 2010, 2011 Free Software Foundation, Inc.
+   Copyright (C) 2009, 2010, 2011, 2012, 2014 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
@@ -19,6 +19,7 @@
 #include "math/categoricals.h"
 #include "math/interaction.h"
 
+#include <float.h>
 #include <stdio.h>
 
 #include "data/case.h"
@@ -32,99 +33,101 @@
 
 #include "gl/xalloc.h"
 
+#define CATEGORICALS_DEBUG 0
+
 struct value_node
 {
   struct hmap_node node;      /* Node in hash map. */
-
   union value val;            /* The value */
-
-};
-
-struct interaction_value
-{
-  struct hmap_node node;        /* Node in hash map. */
-
-  struct ccase *ccase;          /* A case (probably the first in the dataset) which matches this value */
-
-  /* Total of the weights of cases matching this interaction */
-  double cc; 
-
-  void *user_data;            /* A pointer to data which the caller can store stuff */
+  int index;                  /* A zero based unique index for this value */
 };
 
 static struct value_node *
-lookup_value (const struct hmap *map, const union value *val, unsigned int hash, int width)
+lookup_value (const struct hmap *map, const union value *val,
+              unsigned int hash, int width)
 {
-  struct value_node *vn = NULL;
+  struct value_node *vn;
   HMAP_FOR_EACH_WITH_HASH (vn, struct value_node, node, hash, map)
-    {
-      if (value_equal (&vn->val, val, width))
-	break;
-    }
-  
-  return vn;
+    if (value_equal (&vn->val, val, width))
+      return vn;
+  return NULL;
 }
 
+/* A variable used in a categoricals object.  */
 struct variable_node
+  {
+    struct hmap_node node;      /* In struct categorical's 'varmap'. */
+    const struct variable *var; /* The variable. */
+    struct hmap valmap;         /* Contains "struct value_node"s. */
+    union value *values;        /* Values in valmap, as a sorted array. */
+  };
+
+static int
+compare_value_node_3way (const void *vn1_, const void *vn2_, const void *aux)
 {
-  struct hmap_node node;      /* Node in hash map. */
-  const struct variable *var; /* The variable */
+  const struct value_node *const *vn1p = vn1_;
+  const struct value_node *const *vn2p = vn2_;
 
-  struct hmap valmap;         /* A map of value nodes */
-};
+  const struct variable_node *vn = aux;
 
-static void
-dump_interaction (const struct interaction *iact)
-{
-  struct string str = DS_EMPTY_INITIALIZER;
-  interaction_to_string (iact, &str);
-  printf ("Interaction: %s\n", ds_cstr (&str));
-  ds_destroy (&str);
+  return value_compare_3way (&(*vn1p)->val, &(*vn2p)->val,
+                             var_get_width (vn->var));
 }
 
-
 static struct variable_node *
-lookup_variable (const struct hmap *map, const struct variable *var, unsigned int hash)
+lookup_variable (const struct hmap *map, const struct variable *var)
 {
-  struct variable_node *vn = NULL;
-  HMAP_FOR_EACH_WITH_HASH (vn, struct variable_node, node, hash, map)
-    {
-      if (vn->var == var)
-	break;
-      
-      fprintf (stderr, "Warning: Hash table collision\n");
-    }
-  
-  return vn;
+  struct variable_node *vn;
+  HMAP_FOR_EACH_WITH_HASH (vn, struct variable_node, node,
+                           hash_pointer (var, 0), map)
+    if (vn->var == var)
+      return vn;
+  return NULL;
 }
 
-
 struct interact_params
 {
-  /* A map indexed by a interaction_value */
-  struct hmap ivmap;
-
+  /* The interaction, and an array with iact->n_vars elements such that
+     varnodes[x] points to the variable_node for iact->vars[x]. */
   const struct interaction *iact;
+  struct variable_node **varnodes;
+
+  /* An example of each interaction that appears in the data, like a frequency
+     table for 'iact'.  By construction, the number of elements must be less
+     than or equal to 'n_cats'.
 
-  int base_subscript_short;
-  int base_subscript_long;
+     categoricals_update() updates 'ivmap' case-by-case, then
+     categoricals_done() dumps 'ivmap' into 'ivs' and sorts it. */
+  struct hmap ivmap;            /* Contains "struct interaction_value"s. */
+  struct interaction_value **ivs;
 
-  /* The number of distinct values of this interaction */
+  int base_df;
+  int base_cats;
+
+  /* Product of hmap_count(&varnodes[*]->valmap), that is, the maximum number
+     of distinct values of this interaction. */
   int n_cats;
 
-  /* The degrees of freedom for this interaction */
-  int df; 
+  /* Product of degrees of freedom of all the variables. */
+  int df_prod;
 
-  /* A map of interaction_values indexed by subscript */
-  struct interaction_value **reverse_interaction_value_map;
+  double *enc_sum;
 
+  /* Sum of ivs[*]->cc. */
   double cc;
 };
 
+struct interaction_value
+  {
+    struct hmap_node node;    /* In struct interact_params's ivmap. */
+    struct ccase *ccase;      /* A case representative of the interaction. */
+    double cc;                /* Total weight of cases for this interaction. */
+    void *user_data;
+  };
 
-/* Comparison function to sort the reverse_value_map in ascending order */
 static int
-compare_interaction_value_3way (const void *vn1_, const void *vn2_, const void *aux)
+compare_interaction_value_3way (const void *vn1_, const void *vn2_,
+                                const void *aux)
 {
   const struct interaction_value *const *vn1p = vn1_;
   const struct interaction_value *const *vn2p = vn2_;
@@ -139,128 +142,148 @@ struct categoricals
   /* The weight variable */
   const struct variable *wv;
 
-  /* An array of interact_params */
-  struct interact_params *iap;
-
-  /* Map whose members are the union of the variables which comprise IAP */
-  struct hmap varmap;
-
-  /* The size of IAP. (ie, the number of interactions involved.) */
+  struct interact_params *iap;  /* Interaction parameters. */
   size_t n_iap;
 
-  /* The number of categorical variables which contain entries.
-     In the absence of missing values, this will be equal to N_IAP */
-  size_t n_vars;
-
-  size_t df_sum;
+  /* Contains a "struct variable_node" for each variable in 'iap'. */
+  struct hmap varmap;
 
   /* A map to enable the lookup of variables indexed by subscript.
      This map considers only the N - 1 of the N variables.
-   */
-  int *reverse_variable_map_short;
-
-  /* Like the above, but uses all N variables */
-  int *reverse_variable_map_long;
+  */
+  int *df_to_iact; /* 'df_sum' elements. */
+  size_t df_sum;
 
+  /* Like the above, but uses all N variables. */
+  int *cat_to_iact; /* 'n_cats_total' elements. */
   size_t n_cats_total;
 
   struct pool *pool;
 
-  /* Missing values to be excluded */
-  enum mv_class exclude;
+  /* Missing values in the factor variables to be excluded */
+  enum mv_class fctr_excl;
 
-  /* Function to be called on each update */
-  update_func *update;
+  const void *aux1;
+  void *aux2;
 
-  /* Function specified by the caller to create user_data */
-  user_data_create_func *user_data_create;
+  bool sane;
 
-  /* Auxilliary data to be passed to update and user_data_create_func*/
-  void *aux1;
-  void *aux2;
+  const struct payload *payload;
 };
 
 
-static void
-categoricals_dump (const struct categoricals *cat)
+bool
+categoricals_isbalanced (const struct categoricals *cat)
 {
-  int i;
-
-  printf ("Reverse Variable Map (short):\n");
-  for (i = 0; i < cat->df_sum; ++i)
-    {
-      printf (" %d", cat->reverse_variable_map_short[i]);
-    }
-  printf ("\n");
-
-  printf ("Reverse Variable Map (long):\n");
-  for (i = 0; i < cat->n_cats_total; ++i)
-    {
-      printf (" %d", cat->reverse_variable_map_long[i]);
-    }
-  printf ("\n");
-
-
-  printf ("Number of interactions %d\n", cat->n_iap);
-  for (i = 0 ; i < cat->n_iap; ++i)
+  for (int i = 0 ; i < cat->n_iap; ++i)
     {
       int v;
-      struct string str;
       const struct interact_params *iap = &cat->iap[i];
-      const struct interaction *iact = iap->iact;
 
-      ds_init_empty (&str);
-      interaction_to_string (iact, &str);
-
-      printf ("\nInteraction: %s (n: %d; df: %d ); ", ds_cstr (&str), iap->n_cats, iap->df);
-      ds_destroy (&str);
-      printf ("Base subscript: %d\n", iap->base_subscript_short);
-
-      printf ("\t(");
+      double oval = -1.0;
       for (v = 0; v < hmap_count (&iap->ivmap); ++v)
-	{
-	  int vv;
-	  const struct interaction_value *iv = iap->reverse_interaction_value_map[v];
-	  
-	  if (v > 0)  printf ("   ");
-	  printf ("{");
-	  for (vv = 0; vv < iact->n_vars; ++vv)
-	    {
-	      const struct variable *var = iact->vars[vv];
-	      const union value *val = case_data (iv->ccase, var);
-	      
-	      printf ("%g", val->f);
-	      if (vv < iact->n_vars - 1)
-		printf (", ");
-	    }
-	  printf ("}");
-	}
-      printf (")\n");
+        {
+          const struct interaction_value *iv = iap->ivs[v];
+          if (oval == -1.0)
+            oval = iv->cc;
+          if (oval != iv->cc)
+            return false;
+        }
     }
+  return true;
 }
 
 
+static void
+categoricals_dump (const struct categoricals *cat)
+{
+  if (CATEGORICALS_DEBUG)
+    {
+      int i;
+
+      printf ("df to interaction map:\n");
+      for (i = 0; i < cat->df_sum; ++i)
+        printf (" %d", cat->df_to_iact[i]);
+      printf ("\n");
+
+      printf ("Category to interaction map:\n");
+      for (i = 0; i < cat->n_cats_total; ++i)
+        printf (" %d", cat->cat_to_iact[i]);
+      printf ("\n");
+
+      printf ("Number of interactions %zu\n", cat->n_iap);
+      for (i = 0 ; i < cat->n_iap; ++i)
+        {
+          int v;
+          struct string str;
+          const struct interact_params *iap = &cat->iap[i];
+          const struct interaction *iact = iap->iact;
+
+          ds_init_empty (&str);
+          interaction_to_string (iact, &str);
+
+          printf ("\nInteraction: \"%s\" (number of categories: %d); ", ds_cstr (&str), iap->n_cats);
+          ds_destroy (&str);
+          printf ("Base index (df/categories): %d/%d\n", iap->base_df, iap->base_cats);
+
+          printf ("\t(");
+          for (v = 0; v < hmap_count (&iap->ivmap); ++v)
+            {
+              int vv;
+              const struct interaction_value *iv = iap->ivs[v];
+
+              if (v > 0)  printf ("   ");
+              printf ("{");
+              for (vv = 0; vv < iact->n_vars; ++vv)
+                {
+                  const struct variable *var = iact->vars[vv];
+                  const union value *val = case_data (iv->ccase, var);
+                  struct variable_node *vn = iap->varnodes[vv];
+                  const int width = var_get_width (var);
+                  unsigned int valhash = value_hash (val, width, 0);
+                  struct value_node *valn = lookup_value (&vn->valmap, val, valhash, width);
+
+                  assert (vn->var == var);
+
+                  printf ("%.*g(%d)", DBL_DIG + 1, val->f, valn->index);
+                  if (vv < iact->n_vars - 1)
+                    printf (", ");
+                }
+              printf ("}");
+            }
+          printf (")\n");
+        }
+    }
+}
+
 void
 categoricals_destroy (struct categoricals *cat)
 {
-  struct variable_node *vn = NULL;
-  int i;
-  for (i = 0; i < cat->n_iap; ++i)
+  if (!cat)
+    return;
+
+  for (int i = 0; i < cat->n_iap; ++i)
     {
-      struct interaction_value *iv = NULL;
-      /* Interate over each interaction value, and unref any cases that we reffed */
+      /* Unref any cases that we reffed. */
+      struct interaction_value *iv;
       HMAP_FOR_EACH (iv, struct interaction_value, node, &cat->iap[i].ivmap)
-	{
-	  case_unref (iv->ccase);
-	}
+        {
+          if (cat->payload && cat->payload->destroy)
+            cat->payload->destroy (cat->aux1, cat->aux2, iv->user_data);
+          case_unref (iv->ccase);
+        }
+
+      free (cat->iap[i].enc_sum);
       hmap_destroy (&cat->iap[i].ivmap);
     }
+  free (cat->iap);
+
+  /* Interate over each variable and delete its value map.
 
-  /* Interate over each variable and delete its value map */
+     The values themselves are part of the pool. */
+  struct variable_node *vn;
   HMAP_FOR_EACH (vn, struct variable_node, node, &cat->varmap)
-    {
-      hmap_destroy (&vn->valmap);
-    }
+    hmap_destroy (&vn->valmap);
 
   hmap_destroy (&cat->varmap);
 
@@ -269,92 +292,86 @@ categoricals_destroy (struct categoricals *cat)
   free (cat);
 }
 
-
-
 static struct interaction_value *
-lookup_case (const struct hmap *map, const struct interaction *iact, const struct ccase *c)
+lookup_case (const struct hmap *map, const struct interaction *iact,
+             const struct ccase *c)
 {
-  struct interaction_value *iv = NULL;
-  size_t hash = interaction_case_hash (iact, c);
-
+  size_t hash = interaction_case_hash (iact, c, 0);
+  struct interaction_value *iv;
   HMAP_FOR_EACH_WITH_HASH (iv, struct interaction_value, node, hash, map)
-    {
-      if (interaction_case_equal (iact, c, iv->ccase))
-	break;
-
-      fprintf (stderr, "Warning: Hash table collision\n");
-    }
+    if (interaction_case_equal (iact, c, iv->ccase))
+      return iv;
+  return NULL;
+}
 
-  return iv;
+/* Returns true iff CAT is sane, that is, if it is complete and has at least
+   one value. */
+bool
+categoricals_sane (const struct categoricals *cat)
+{
+  return cat->sane;
 }
 
+/* Creates and returns a new categoricals object whose variables come from the
+   N_INTER interactions objects in the array starting at INTER.  (The INTER
+   objects must outlive the categoricals object because it uses them
+   internally.)
 
+   FCTR_EXCL determines which cases are listwise ignored by
+   categoricals_update(). */
 struct categoricals *
-categoricals_create (struct interaction *const*inter, size_t n_inter,
-		     const struct variable *wv, enum mv_class exclude,
-		     user_data_create_func *udf,
-		     update_func *update, void *aux1, void *aux2
-		     )
-{
-  size_t i;
-  struct categoricals *cat = xmalloc (sizeof *cat);
-  
+categoricals_create (struct interaction *const *inter, size_t n_inter,
+                     const struct variable *wv, enum mv_class fctr_excl)
+{
+  struct categoricals *cat = XZALLOC (struct categoricals);
+  cat->iap = pool_calloc (cat->pool, n_inter, sizeof *cat->iap);
   cat->n_iap = n_inter;
   cat->wv = wv;
-  cat->n_cats_total = 0;
-  cat->n_vars = 0;
-  cat->reverse_variable_map_short = NULL;
-  cat->reverse_variable_map_long = NULL;
   cat->pool = pool_create ();
-  cat->exclude = exclude;
-  cat->update = update;
-  cat->user_data_create = udf;
-
-  cat->aux1 = aux1;
-  cat->aux2 = aux2;
-
-  cat->iap = pool_calloc (cat->pool, cat->n_iap, sizeof *cat->iap);
+  cat->fctr_excl = fctr_excl;
 
   hmap_init (&cat->varmap);
-  for (i = 0 ; i < cat->n_iap; ++i)
+  for (size_t i = 0; i < cat->n_iap; ++i)
     {
-      int v;
-      hmap_init (&cat->iap[i].ivmap);
-      cat->iap[i].iact = inter[i];
-      cat->iap[i].cc = 0.0;
-      for (v = 0; v < inter[i]->n_vars; ++v)
-	{
-	  const struct variable *var = inter[i]->vars[v];
-	  unsigned int hash = hash_pointer (var, 0);
-	  struct variable_node *vn = lookup_variable (&cat->varmap, var, hash);
-	  if (vn == NULL)
-	    {
-	      vn = pool_malloc (cat->pool, sizeof *vn);
-	      vn->var = var;
-	      hmap_init (&vn->valmap);
-
-	      hmap_insert (&cat->varmap, &vn->node,  hash);
-	    }
-	}
+      struct interact_params *iap = &cat->iap[i];
+      hmap_init (&iap->ivmap);
+      iap->iact = inter[i];
+      iap->cc = 0.0;
+      iap->varnodes = pool_nmalloc (cat->pool, iap->iact->n_vars,
+                                    sizeof *iap->varnodes);
+      for (size_t v = 0; v < inter[i]->n_vars; ++v)
+        {
+          const struct variable *var = inter[i]->vars[v];
+          struct variable_node *vn = lookup_variable (&cat->varmap, var);
+          if (!vn)
+            {
+              vn = pool_malloc (cat->pool, sizeof *vn);
+              vn->var = var;
+              vn->values = NULL;
+              hmap_init (&vn->valmap);
+              hmap_insert (&cat->varmap, &vn->node, hash_pointer (var, 0));
+            }
+          iap->varnodes[v] = vn;
+        }
     }
 
   return cat;
 }
 
-
-
 void
 categoricals_update (struct categoricals *cat, const struct ccase *c)
 {
-  int i;
-  struct variable_node *vn = NULL;
-  const double weight = cat->wv ? case_data (c, cat->wv)->f : 1.0;
+  if (!cat)
+    return;
+  assert (!cat->df_to_iact);
+  assert (!cat->cat_to_iact);
 
-  assert (NULL == cat->reverse_variable_map_short);
-  assert (NULL == cat->reverse_variable_map_long);
+  double weight;
+  weight = cat->wv ? case_num (c, cat->wv) : 1.0;
+  weight = var_force_valid_weight (cat->wv, weight, NULL);
 
-  /* Interate over each variable, and add the value of that variable
-     to the appropriate map, if it's not already present. */
+  /* Update the frequency table for each variable. */
+  struct variable_node *vn;
   HMAP_FOR_EACH (vn, struct variable_node, node, &cat->varmap)
     {
       const int width = var_get_width (vn->var);
@@ -363,280 +380,389 @@ categoricals_update (struct categoricals *cat, const struct ccase *c)
 
       struct value_node *valn = lookup_value (&vn->valmap, val, hash, width);
       if (valn == NULL)
-	{
-	  valn = pool_malloc (cat->pool, sizeof *valn);
-	  value_init (&valn->val, width);
-	  value_copy (&valn->val, val, width);
-	  hmap_insert (&vn->valmap, &valn->node, hash);
-	}
-    }	  
-  
-
-  for (i = 0 ; i < cat->n_iap; ++i)
-    {
-      const struct interaction *iact = cat->iap[i].iact;
-
-      //      if ( interaction_case_is_missing (iact, c, cat->exclude))
-      //         continue;
-
-      size_t hash = interaction_case_hash (iact, c);
-      struct interaction_value *node = lookup_case (&cat->iap[i].ivmap, iact, c);
-
-      if ( NULL == node)
-	{
-	  node = pool_malloc (cat->pool, sizeof *node);
-
-	  node->ccase = case_ref (c);
-	  node->cc = weight;
-
-	  hmap_insert (&cat->iap[i].ivmap, &node->node, hash);
+        {
+          valn = pool_malloc (cat->pool, sizeof *valn);
+          valn->index = -1;
+          value_init_pool (cat->pool, &valn->val, width);
+          value_copy (&valn->val, val, width);
+          hmap_insert (&vn->valmap, &valn->node, hash);
+        }
+    }
 
-	  if (cat->user_data_create)
-	    node->user_data = cat->user_data_create (cat->aux1, cat->aux2);
-	}
+  /* Update the frequency table for full interactions. */
+  for (int i = 0; i < cat->n_iap; ++i)
+    {
+      struct interact_params *iap = &cat->iap[i];
+      const struct interaction *iact = iap->iact;
+      if (interaction_case_is_missing (iact, c, cat->fctr_excl))
+        continue;
+
+      unsigned int hash = interaction_case_hash (iact, c, 0);
+      struct interaction_value *node = lookup_case (&iap->ivmap, iact, c);
+      if (!node)
+        {
+          node = pool_malloc (cat->pool, sizeof *node);
+          node->ccase = case_ref (c);
+          node->cc = weight;
+
+          hmap_insert (&iap->ivmap, &node->node, hash);
+
+          if (cat->payload)
+            node->user_data = cat->payload->create (cat->aux1, cat->aux2);
+        }
       else
-	{
-	  node->cc += weight;
-	}
-      cat->iap[i].cc += weight;
+        node->cc += weight;
+      iap->cc += weight;
 
-      if (cat->update)
-      	cat->update (node->user_data, cat->exclude, cat->wv, NULL, c, cat->aux1, cat->aux2);
+      if (cat->payload)
+        cat->payload->update (cat->aux1, cat->aux2, node->user_data, c,
+                              weight);
     }
 }
 
-/* Return the number of categories (distinct values) for interction N */
+/* Return the number of categories (distinct values) for interaction IDX in
+   CAT. */
 size_t
-categoricals_n_count (const struct categoricals *cat, size_t n)
+categoricals_n_count (const struct categoricals *cat, size_t idx)
 {
-  return hmap_count (&cat->iap[n].ivmap);
+  return hmap_count (&cat->iap[idx].ivmap);
 }
 
-
+/* Return the total number of categories across all interactions in CAT. */
 size_t
-categoricals_df (const struct categoricals *cat, size_t n)
+categoricals_n_total (const struct categoricals *cat)
 {
-  return cat->iap[n].df;
+  return categoricals_is_complete (cat) ? cat->n_cats_total : 0;
 }
 
-
-/* Return the total number of categories */
+/* Returns the number of degrees of freedom for interaction IDX within CAT. */
 size_t
-categoricals_n_total (const struct categoricals *cat)
+categoricals_df (const struct categoricals *cat, size_t idx)
 {
-  assert (cat->reverse_variable_map_long);
-
-  return cat->n_cats_total;
+  const struct interact_params *iap = &cat->iap[idx];
+  return iap->df_prod;
 }
 
+/* Returns the total degrees of freedom for CAT. */
 size_t
 categoricals_df_total (const struct categoricals *cat)
 {
-  return cat->df_sum;
+  return cat ? cat->df_sum : 0;
 }
 
-/* This function must be called *before* any call to categoricals_get_*_by subscript and
- *after* all calls to categoricals_update */
+/* Returns true iff categoricals_done() has been called for CAT. */
+bool
+categoricals_is_complete (const struct categoricals *cat)
+{
+  return cat->df_to_iact != NULL;
+}
+
+/* This function must be called (once) before any call to the *_by_subscript or
+  *_by_category functions, but AFTER any calls to categoricals_update.  If this
+  function returns false, then no calls to _by_subscript or *_by_category are
+  allowed. */
 void
 categoricals_done (const struct categoricals *cat_)
 {
-  /* Implementation Note: Whilst this function is O(n) in cat->n_cats_total, in most
-     uses it will be more efficient that using a tree based structure, since it
-     is called only once, and means that subsequent lookups will be O(1).
-
-     1 call of O(n) + 10^9 calls of O(1) is better than 10^9 calls of O(log n).
-  */
   struct categoricals *cat = CONST_CAST (struct categoricals *, cat_);
-  int v;
-  int i;
-  int idx_short = 0;
-  int idx_long = 0;
-  cat->df_sum = 0;
-  cat->n_cats_total = 0;
+  if (!cat || categoricals_is_complete (cat))
+    return;
 
-  /* Calculate the degrees of freedom, and the number of categories */
-  for (i = 0 ; i < cat->n_iap; ++i)
+  /* Assign 'index' to each variables' value_nodes, counting up from 0 in
+     ascending order by value. */
+  struct variable_node *vn;
+  HMAP_FOR_EACH (vn, struct variable_node, node, &cat->varmap)
     {
-      const struct interaction *iact = cat->iap[i].iact;
-
-      cat->iap[i].df = 1;
-      cat->iap[i].n_cats = 1;
+      size_t n_vals = hmap_count (&vn->valmap);
+      if (!n_vals)
+        {
+          cat->sane = false;
+          return;
+        }
+
+      struct value_node **nodes = XCALLOC (n_vals,  struct value_node *);
+      int x = 0;
+      struct value_node *valnd;
+      HMAP_FOR_EACH (valnd, struct value_node, node, &vn->valmap)
+        nodes[x++] = valnd;
+      sort (nodes, n_vals, sizeof *nodes, compare_value_node_3way, vn);
+      for (x = 0; x < n_vals; ++x)
+        nodes[x]->index = x;
+      free (nodes);
+    }
 
-      for (v = 0 ; v < iact->n_vars; ++v)
-	{
-	  const struct variable *var = iact->vars[v];
+  /* Calculate the degrees of freedom, and the number of categories. */
+  cat->df_sum = 0;
+  cat->n_cats_total = 0;
+  for (int i = 0 ; i < cat->n_iap; ++i)
+    {
+      struct interact_params *iap = &cat->iap[i];
+      const struct interaction *iact = iap->iact;
 
-	  struct variable_node *vn = lookup_variable (&cat->varmap, var, hash_pointer (var, 0));
+      iap->df_prod = 1;
+      iap->n_cats = 1;
+      for (int v = 0 ; v < iact->n_vars; ++v)
+        {
+          size_t n_vals = hmap_count (&iap->varnodes[v]->valmap);
 
-	  cat->iap[i].df *= hmap_count (&vn->valmap) - 1;
-	  cat->iap[i].n_cats *= hmap_count (&vn->valmap);
-	}
+          iap->df_prod *= n_vals - 1;
+          iap->n_cats *= n_vals;
+        }
 
-      cat->df_sum += cat->iap[i].df;
-      cat->n_cats_total += cat->iap[i].n_cats;
+      if (iact->n_vars > 0)
+        cat->df_sum += iap->df_prod;
+      cat->n_cats_total += iap->n_cats;
     }
 
 
-  cat->reverse_variable_map_short = pool_calloc (cat->pool,
-						 cat->df_sum,
-						 sizeof *cat->reverse_variable_map_short);
+  cat->df_to_iact = pool_calloc (cat->pool, cat->df_sum,
+                                 sizeof *cat->df_to_iact);
 
-  cat->reverse_variable_map_long = pool_calloc (cat->pool,
-						cat->n_cats_total,
-						sizeof *cat->reverse_variable_map_long);
+  cat->cat_to_iact = pool_calloc (cat->pool, cat->n_cats_total,
+                                  sizeof *cat->cat_to_iact);
 
-  for (i = 0 ; i < cat->n_iap; ++i)
+  int idx_df = 0;
+  int idx_cat = 0;
+  for (int i = 0; i < cat->n_iap; ++i)
     {
-      struct interaction_value *ivn = NULL;
-      int x = 0;
-      int ii;
       struct interact_params *iap = &cat->iap[i];
 
-      iap->base_subscript_short = idx_short;
-      iap->base_subscript_long = idx_long;
-
-      iap->reverse_interaction_value_map = pool_calloc (cat->pool, iap->n_cats,
-							sizeof *iap->reverse_interaction_value_map);
+      iap->base_df = idx_df;
+      iap->base_cats = idx_cat;
 
+      /* For some purposes (eg CONTRASTS in ONEWAY) the values need to be
+         sorted. */
+      iap->ivs = pool_nmalloc (cat->pool, hmap_count (&iap->ivmap),
+                               sizeof *iap->ivs);
+      int x = 0;
+      struct interaction_value *ivn;
       HMAP_FOR_EACH (ivn, struct interaction_value, node, &iap->ivmap)
-	{
-	  iap->reverse_interaction_value_map[x++] = ivn;
-	}
+        iap->ivs[x++] = ivn;
+      sort (iap->ivs, x, sizeof *iap->ivs,
+            compare_interaction_value_3way, iap);
 
-      assert (x <= iap->n_cats);
+      /* Populate the variable maps. */
+      if (iap->iact->n_vars)
+        for (int j = 0; j < iap->df_prod; ++j)
+          cat->df_to_iact[idx_df++] = i;
 
-      /* For some purposes (eg CONTRASTS in ONEWAY) the values need to be sorted */
-      sort (iap->reverse_interaction_value_map, x, sizeof (*iap->reverse_interaction_value_map),
-	    compare_interaction_value_3way, iap);
+      for (int j = 0; j < iap->n_cats; ++j)
+        cat->cat_to_iact[idx_cat++] = i;
+    }
 
-      /* Fill the remaining values with null */
-      for (ii = x ; ii < iap->n_cats; ++ii)
-	iap->reverse_interaction_value_map[ii] = NULL;
+  categoricals_dump (cat);
 
-      /* Populate the reverse variable maps. */
-      for (ii = 0; ii < iap->df; ++ii)
-	cat->reverse_variable_map_short[idx_short++] = i;
+  /* Tally up the sums for all the encodings */
+  for (int i = 0; i < cat->n_iap; ++i)
+    {
+      struct interact_params *iap = &cat->iap[i];
+      const struct interaction *iact = iap->iact;
 
-      for (ii = 0; ii < iap->n_cats; ++ii)
-	cat->reverse_variable_map_long[idx_long++] = i;
+      const int df = iact->n_vars ? iap->df_prod : 0;
+
+      iap->enc_sum = xcalloc (df, sizeof *iap->enc_sum);
+
+      for (int y = 0; y < hmap_count (&iap->ivmap); ++y)
+        {
+          struct interaction_value *iv = iap->ivs[y];
+          for (int x = iap->base_df;
+               x < iap->base_df + df; ++x)
+            {
+              const double bin = categoricals_get_effects_code_for_case (
+                cat, x, iv->ccase);
+              iap->enc_sum[x - iap->base_df] += bin * iv->cc;
+            }
+          if (cat->payload && cat->payload->calculate)
+            cat->payload->calculate (cat->aux1, cat->aux2, iv->user_data);
+        }
     }
 
-  assert (cat->n_vars <= cat->n_iap);
-
-  //  categoricals_dump (cat);
+  cat->sane = true;
 }
 
+union value *
+categoricals_get_var_values (const struct categoricals *cat,
+                             const struct variable *var, size_t *np)
+{
+  struct variable_node *vn = lookup_variable (&cat->varmap, var);
+  *np = hmap_count (&vn->valmap);
+  if (!vn->values)
+    {
+      vn->values = pool_nalloc (cat->pool, *np, sizeof *vn->values);
+
+      struct value_node *valnd;
+      HMAP_FOR_EACH (valnd, struct value_node, node, &vn->valmap)
+        vn->values[valnd->index] = valnd->val;
+    }
+  return vn->values;
+}
 
-static int
-reverse_variable_lookup_short (const struct categoricals *cat, int subscript)
+static struct interact_params *
+df_to_iap (const struct categoricals *cat, int subscript)
 {
-  assert (cat->reverse_variable_map_short);
   assert (subscript >= 0);
   assert (subscript < cat->df_sum);
 
-  return cat->reverse_variable_map_short[subscript];
+  return &cat->iap[cat->df_to_iact[subscript]];
 }
 
-static int
-reverse_variable_lookup_long (const struct categoricals *cat, int subscript)
+static struct interact_params *
+cat_index_to_iap (const struct categoricals *cat, int cat_index)
 {
-  assert (cat->reverse_variable_map_long);
-  assert (subscript >= 0);
-  assert (subscript < cat->n_cats_total);
+  assert (cat_index >= 0);
+  assert (cat_index < cat->n_cats_total);
 
-  return cat->reverse_variable_map_long[subscript];
+  return &cat->iap[cat->cat_to_iact[cat_index]];
 }
 
-
-/* Return the interaction corresponding to SUBSCRIPT */
+/* Return the interaction corresponding to SUBSCRIPT. */
 const struct interaction *
-categoricals_get_interaction_by_subscript (const struct categoricals *cat, int subscript)
+categoricals_get_interaction_by_subscript (const struct categoricals *cat,
+                                           int subscript)
 {
-  int index = reverse_variable_lookup_short (cat, subscript);
-
-  return cat->iap[index].iact;
+  return df_to_iap (cat, subscript)->iact;
 }
 
-
-/* Return the case corresponding to SUBSCRIPT */
-static const struct ccase *
-categoricals_get_case_by_subscript (const struct categoricals *cat, int subscript)
+double
+categoricals_get_weight_by_subscript (const struct categoricals *cat,
+                                      int subscript)
 {
-  int vindex = reverse_variable_lookup_short (cat, subscript);
-  const struct interact_params *vp = &cat->iap[vindex];
-  const struct interaction_value *vn = vp->reverse_interaction_value_map [subscript - vp->base_subscript_short];
-
-  if ( vn == NULL)
-    return NULL;
-
-  return vn->ccase;
+  return df_to_iap (cat, subscript)->cc;
 }
 
-
 double
-categoricals_get_weight_by_subscript (const struct categoricals *cat, int subscript)
+categoricals_get_sum_by_subscript (const struct categoricals *cat,
+                                   int subscript)
 {
-  int vindex = reverse_variable_lookup_short (cat, subscript);
-  const struct interact_params *vp = &cat->iap[vindex];
-
-  return vp->cc;
+  const struct interact_params *iap = df_to_iap (cat, subscript);
+  return iap->enc_sum[subscript - iap->base_df];
 }
 
-double
-categoricals_get_sum_by_subscript (const struct categoricals *cat, int subscript)
+
+/* Returns unity if the value in case C at SUBSCRIPT is equal to the category
+   for that subscript */
+static double
+categoricals_get_code_for_case (const struct categoricals *cat, int subscript,
+                                const struct ccase *c,
+                                bool effects_coding)
 {
-  int vindex = reverse_variable_lookup_short (cat, subscript);
-  const struct interact_params *vp = &cat->iap[vindex];
+  const struct interaction *iact
+    = categoricals_get_interaction_by_subscript (cat, subscript);
+
+  const struct interact_params *iap = df_to_iap (cat, subscript);
+
+  double result = 1.0;
+  int dfp = 1;
+  for (int v = 0; v < iact->n_vars; ++v)
+    {
+      const struct variable *var = iact->vars[v];
+
+      const union value *val = case_data (c, var);
+      const int width = var_get_width (var);
+
+      const unsigned int hash = value_hash (val, width, 0);
+      const struct value_node *valn
+        = lookup_value (&iap->varnodes[v]->valmap, val, hash, width);
 
-  const struct interaction_value *iv = vp->reverse_interaction_value_map [subscript - vp->base_subscript_short];
+      const int df = hmap_count (&iap->varnodes[v]->valmap) - 1;
+      const int dfpn = dfp * df;
 
-  if (iv == NULL)
-    return 0;
+      if (effects_coding && valn->index == df)
+        result = -result;
+      else
+        {
+          /* Translate subscript into an index for the individual variable. */
+          const int index = ((subscript - iap->base_df) % dfpn) / dfp;
+          if (valn->index != index)
+            return 0.0;
+        }
+      dfp = dfpn;
+    }
 
-  return iv->cc;
+  return result;
 }
 
+
 /* Returns unity if the value in case C at SUBSCRIPT is equal to the category
-   for that subscript */
+   for that subscript. */
 double
-categoricals_get_binary_by_subscript (const struct categoricals *cat, int subscript,
-				      const struct ccase *c)
+categoricals_get_dummy_code_for_case (const struct categoricals *cat,
+                                      int subscript, const struct ccase *c)
 {
-  const struct interaction *iact = categoricals_get_interaction_by_subscript (cat, subscript);
-
-  const struct ccase *c2 =  categoricals_get_case_by_subscript (cat, subscript);
+  return categoricals_get_code_for_case (cat, subscript, c, false);
+}
 
-  if ( c2 == NULL)
-    return 0;
+/* Returns unity if the value in case C at SUBSCRIPT is equal to the category
+   for that subscript.
+   Else if it is the last category, return -1.
+   Otherwise return 0.
+ */
+double
+categoricals_get_effects_code_for_case (const struct categoricals *cat,
+                                        int subscript, const struct ccase *c)
+{
+  return categoricals_get_code_for_case (cat, subscript, c, true);
+}
 
-  return interaction_case_equal (iact, c, c2);
+/* Return a case containing the set of values corresponding to
+   the Nth Category of the IACTth interaction */
+const struct ccase *
+categoricals_get_case_by_category_real (const struct categoricals *cat,
+                                        int iact, int n)
+{
+  const struct interact_params *iap = &cat->iap[iact];
+  return n < hmap_count (&iap->ivmap) ? iap->ivs[n]->ccase : NULL;
 }
 
+/* Return a the user data corresponding to the Nth Category of the IACTth
+   interaction. */
+void *
+categoricals_get_user_data_by_category_real (const struct categoricals *cat,
+                                             int iact, int n)
+{
+  const struct interact_params *iap = &cat->iap[iact];
+  return n < hmap_count (&iap->ivmap) ? iap->ivs[n]->user_data : NULL;
+}
 
-size_t
-categoricals_get_n_variables (const struct categoricals *cat)
+int
+categoricals_get_value_index_by_category_real (const struct categoricals *cat,
+                                               int iact_idx, int cat_idx,
+                                               int var_idx)
 {
-  printf ("%s\n", __FUNCTION__);
-  return cat->n_vars;
+  const struct interact_params *iap = &cat->iap[iact_idx];
+  const struct interaction_value *ivn = iap->ivs[cat_idx];
+  const struct variable *var = iap->iact->vars[var_idx];
+  const struct variable_node *vn = iap->varnodes[var_idx];
+  const union value *val = case_data (ivn->ccase, var);
+  int width = var_get_width (var);
+  unsigned int hash = value_hash (val, width, 0);
+  return lookup_value (&vn->valmap, val, hash, width)->index;
 }
 
-/* Return a case containing the set of values corresponding to SUBSCRIPT */
+/* Return a case containing the set of values corresponding to CAT_INDEX. */
 const struct ccase *
-categoricals_get_case_by_category (const struct categoricals *cat, int subscript)
+categoricals_get_case_by_category (const struct categoricals *cat,
+                                   int cat_index)
 {
-  int vindex = reverse_variable_lookup_long (cat, subscript);
-  const struct interact_params *vp = &cat->iap[vindex];
-  const struct interaction_value *vn = vp->reverse_interaction_value_map [subscript - vp->base_subscript_long];
-
+  const struct interact_params *iap = cat_index_to_iap (cat, cat_index);
+  const struct interaction_value *vn = iap->ivs[cat_index - iap->base_cats];
   return vn->ccase;
 }
 
 void *
-categoricals_get_user_data_by_category (const struct categoricals *cat, int subscript)
+categoricals_get_user_data_by_category (const struct categoricals *cat,
+                                        int cat_index)
 {
-  int vindex = reverse_variable_lookup_long (cat, subscript);
-  const struct interact_params *vp = &cat->iap[vindex];
-
-  const struct interaction_value *iv = vp->reverse_interaction_value_map [subscript - vp->base_subscript_long];
+  const struct interact_params *iap = cat_index_to_iap (cat, cat_index);
+  const struct interaction_value *iv = iap->ivs[cat_index - iap->base_cats];
   return iv->user_data;
 }
+
+void
+categoricals_set_payload (struct categoricals *cat, const struct payload *p,
+                          const void *aux1, void *aux2)
+{
+  cat->payload = p;
+  cat->aux1 = aux1;
+  cat->aux2 = aux2;
+}