X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fmath%2Fcategoricals.c;h=83326c3f006789814c4930feed8d85d15db95155;hb=b9f712f8911170fcc049c6d7d83b6887185de4dd;hp=6002d8c179aa09529fa7740a676ab7329f2255fa;hpb=ef40d0ff4989b13360acb0504ac5a8fbeff31c16;p=pspp

diff --git a/src/math/categoricals.c b/src/math/categoricals.c
index 6002d8c179..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 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
@@ -16,368 +16,753 @@
 
 #include <config.h>
 
+#include "math/categoricals.h"
+#include "math/interaction.h"
+
+#include <float.h>
 #include <stdio.h>
 
-#include "categoricals.h"
+#include "data/case.h"
+#include "data/value.h"
+#include "data/variable.h"
+#include "libpspp/array.h"
+#include "libpspp/hmap.h"
+#include "libpspp/pool.h"
+#include "libpspp/str.h"
+#include "libpspp/hash-functions.h"
 
-#include <gl/xalloc.h>
-#include <data/variable.h>
-#include <data/case.h>
-#include <data/value.h>
-#include <libpspp/hmap.h>
-#include <libpspp/pool.h>
+#include "gl/xalloc.h"
 
-#include <libpspp/str.h>
+#define CATEGORICALS_DEBUG 0
 
 struct value_node
 {
   struct hmap_node node;      /* Node in hash map. */
-  union value value;          /* The value being labeled. */
-  double cc;                  /* The total of the weights of cases with this value */
-  int subscript;              /* A zero based integer, unique within the variable.
-				 Can be used as an index into an array */
+  union value val;            /* The value */
+  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)
+{
+  struct value_node *vn;
+  HMAP_FOR_EACH_WITH_HASH (vn, struct value_node, node, hash, map)
+    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. */
+  };
 
-struct var_params
+static int
+compare_value_node_3way (const void *vn1_, const void *vn2_, const void *aux)
 {
-  /* A map indexed by a union values */
-  struct hmap map;
+  const struct value_node *const *vn1p = vn1_;
+  const struct value_node *const *vn2p = vn2_;
 
-  const struct variable *var;
+  const struct variable_node *vn = aux;
 
-  int base_subscript;
+  return value_compare_3way (&(*vn1p)->val, &(*vn2p)->val,
+                             var_get_width (vn->var));
+}
 
-  /* The number of distinct values of this variable */
+static struct variable_node *
+lookup_variable (const struct hmap *map, const struct variable *var)
+{
+  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
+{
+  /* 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'.
+
+     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;
+
+  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;
 
-  /* A map of values indexed by subscript */
-  const struct value_node **reverse_value_map;
+  /* Product of degrees of freedom of all the variables. */
+  int df_prod;
 
-  /* Total of the weights of this variable */
-  double cc; 
+  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;
+  };
+
+static int
+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_;
+
+  const struct interact_params *iap = aux;
+
+  return interaction_case_cmp_3way (iap->iact, (*vn1p)->ccase, (*vn2p)->ccase);
+}
 
 struct categoricals
 {
   /* The weight variable */
   const struct variable *wv;
 
+  struct interact_params *iap;  /* Interaction parameters. */
+  size_t n_iap;
 
-  /* An array of var_params */
-  struct var_params *vp;
+  /* Contains a "struct variable_node" for each variable in 'iap'. */
+  struct hmap varmap;
 
-  /* The size of VP. (ie, the number of variables involved.) */
-  size_t n_vp;
-
-  /* The number of categorical variables which contain entries.
-     In the absence of missing values, this will be equal to N_VP */
-  size_t n_vars;
-
-  /* A map to enable the lookup of variables indexed by subscript */
-  int *reverse_variable_map;
+  /* A map to enable the lookup of variables indexed by subscript.
+     This map considers only the N - 1 of the N variables.
+  */
+  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;
+
+  const void *aux1;
+  void *aux2;
+
+  bool sane;
+
+  const struct payload *payload;
 };
 
 
-void
-categoricals_destroy ( struct categoricals *cat)
+bool
+categoricals_isbalanced (const struct categoricals *cat)
 {
-  int i;
-  for (i = 0 ; i < cat->n_vp; ++i)
-    hmap_destroy (&cat->vp[i].map);
-
-  pool_destroy (cat->pool);
-  free (cat);
+  for (int i = 0 ; i < cat->n_iap; ++i)
+    {
+      int v;
+      const struct interact_params *iap = &cat->iap[i];
+
+      double oval = -1.0;
+      for (v = 0; v < hmap_count (&iap->ivmap); ++v)
+        {
+          const struct interaction_value *iv = iap->ivs[v];
+          if (oval == -1.0)
+            oval = iv->cc;
+          if (oval != iv->cc)
+            return false;
+        }
+    }
+  return true;
 }
 
 
-void
+static void
 categoricals_dump (const struct categoricals *cat)
 {
-  int v;
-
-  for (v = 0 ; v < cat->n_vp; ++v)
+  if (CATEGORICALS_DEBUG)
     {
-      const struct var_params *vp = &cat->vp[v];
-      const struct hmap *m = &vp->map;
-      struct hmap_node *node ;
-      int x;
-     
-      printf ("\n%s (%d)  CC=%g n_cats=%d:\n", 
-	      var_get_name (vp->var), vp->base_subscript, vp->cc, vp->n_cats);
-
-      printf ("Reverse map\n");
-      for (x = 0 ; x < vp->n_cats; ++x)
-	{
-	  struct string s;
-	  const struct value_node *vn = vp->reverse_value_map[x];
-	  ds_init_empty (&s);
-	  var_append_value_name (vp->var, &vn->value, &s);
-	  printf ("Value for %d is %s\n", x, ds_cstr(&s));
-	  ds_destroy (&s);
-	}
-
-      printf ("\nForward map\n");
-      for (node = hmap_first (m); node; node = hmap_next (m, node))
-	{
-	  struct string s;
-	  ds_init_empty (&s);
-	  const struct value_node *vn = HMAP_DATA (node, struct value_node, node);
-	  var_append_value_name (vp->var, &vn->value, &s);
-	  printf ("Value: %s; Index %d; CC %g\n",
-		  ds_cstr (&s),
-		  vn->subscript, vn->cc);
-	  ds_destroy (&s);
-	}
-    }
-
-  assert (cat->n_vars <= cat->n_vp);
+      int i;
 
-  printf ("\n");
-  printf ("Number of categorical variables: %d\n", cat->n_vp);
-  printf ("Number of non-empty categorical variables: %d\n", cat->n_vars);
-  printf ("Total number of categories: %d\n", cat->n_cats_total);
+      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");
+        }
+    }
+}
 
-  printf ("\nReverse variable map:\n");
+void
+categoricals_destroy (struct categoricals *cat)
+{
+  if (!cat)
+    return;
 
-  for (v = 0 ; v < cat->n_cats_total - cat->n_vars; ++v)
-    printf ("%d ", cat->reverse_variable_map[v]);
-  printf ("\n");
-}
+  for (int i = 0; i < cat->n_iap; ++i)
+    {
+      /* Unref any cases that we reffed. */
+      struct interaction_value *iv;
+      HMAP_FOR_EACH (iv, struct interaction_value, node, &cat->iap[i].ivmap)
+        {
+          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.
 
+     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);
 
-static struct value_node *
-lookup_value (const struct hmap *map, const struct variable *var, const union value *val)
-{
-  struct value_node *foo;
-  unsigned int width = var_get_width (var);
-  size_t hash = value_hash (val, width, 0);
+  hmap_destroy (&cat->varmap);
 
-  HMAP_FOR_EACH_WITH_HASH (foo, struct value_node, node, hash, map)
-    {
-      if (value_equal (val, &foo->value, width))
-	break;
+  pool_destroy (cat->pool);
 
-      fprintf (stderr, "Warning: Hash table collision\n");
-    }
+  free (cat);
+}
 
-  return foo;
+static struct interaction_value *
+lookup_case (const struct hmap *map, const struct interaction *iact,
+             const struct ccase *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))
+      return iv;
+  return NULL;
 }
 
+/* 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 (const struct variable **v, size_t n_vars,
-		     const struct variable *wv, enum mv_class exclude)
+categoricals_create (struct interaction *const *inter, size_t n_inter,
+                     const struct variable *wv, enum mv_class fctr_excl)
 {
-  size_t i;
-  struct categoricals *cat = xmalloc (sizeof *cat);
-  
-  cat->n_vp = n_vars;
+  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 = NULL;
   cat->pool = pool_create ();
-  cat->exclude = exclude;
+  cat->fctr_excl = fctr_excl;
 
-  cat->vp = pool_calloc (cat->pool, cat->n_vp, sizeof *cat->vp);
-
-  for (i = 0 ; i < cat->n_vp; ++i)
+  hmap_init (&cat->varmap);
+  for (size_t i = 0; i < cat->n_iap; ++i)
     {
-      hmap_init (&cat->vp[i].map);
-      cat->vp[i].var = v[i];
+      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)
 {
-  size_t i;
-  
-  const double weight = cat->wv ? case_data (c, cat->wv)->f : 1.0;
-
-  assert (NULL == cat->reverse_variable_map);
-
-  for (i = 0 ; i < cat->n_vp; ++i)
+  if (!cat)
+    return;
+  assert (!cat->df_to_iact);
+  assert (!cat->cat_to_iact);
+
+  double weight;
+  weight = cat->wv ? case_num (c, cat->wv) : 1.0;
+  weight = var_force_valid_weight (cat->wv, weight, NULL);
+
+  /* Update the frequency table for each variable. */
+  struct variable_node *vn;
+  HMAP_FOR_EACH (vn, struct variable_node, node, &cat->varmap)
     {
-      const struct variable *var = cat->vp[i].var;
-      unsigned int width = var_get_width (var);
-      const union value *val = case_data (c, var);
-      size_t hash;
-      struct value_node *node ;
-
-      if ( var_is_value_missing (var, val, cat->exclude))
-	continue;
-
-      hash = value_hash (val, width, 0);
-      node = lookup_value (&cat->vp[i].map, var, val);
-
-      if ( NULL == node)
-	{
-	  node = pool_malloc (cat->pool, sizeof *node);
-
-	  value_init (&node->value, width);
-	  value_copy (&node->value, val, width);
-	  node->cc = 0.0;
-
-	  hmap_insert (&cat->vp[i].map, &node->node,  hash);
-	  cat->n_cats_total++;
-	  
-	  if ( 0 == cat->vp[i].n_cats)
-	    cat->n_vars++;
-
-	  node->subscript = cat->vp[i].n_cats++ ;
-	}
+      const int width = var_get_width (vn->var);
+      const union value *val = case_data (c, vn->var);
+      unsigned int hash = value_hash (val, width, 0);
+
+      struct value_node *valn = lookup_value (&vn->valmap, val, hash, width);
+      if (valn == NULL)
+        {
+          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);
+        }
+    }
 
-      node->cc += weight;
-      cat->vp[i].cc += weight;
+  /* 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;
+      iap->cc += weight;
+
+      if (cat->payload)
+        cat->payload->update (cat->aux1, cat->aux2, node->user_data, c,
+                              weight);
     }
 }
 
-/* Return the number of categories (distinct values) for variable 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->vp[n].map);
+  return hmap_count (&cat->iap[idx].ivmap);
 }
 
+/* Return the total number of categories across all interactions in CAT. */
+size_t
+categoricals_n_total (const struct categoricals *cat)
+{
+  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_total (const struct categoricals *cat)
+categoricals_df (const struct categoricals *cat, size_t idx)
 {
-  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 ? cat->df_sum : 0;
+}
+
+/* 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 *before* any call to categoricals_get_*_by subscript an
- *after* all calls to categoricals_update */
+/* 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 (struct categoricals *cat)
+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).
+  struct categoricals *cat = CONST_CAST (struct categoricals *, cat_);
+  if (!cat || categoricals_is_complete (cat))
+    return;
+
+  /* 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)
+    {
+      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);
+    }
 
-     1 call of O(n) + 10^9 calls of O(1) is better than 10^9 calls of O(log n).
-  */
-  int v;
-  int idx = 0;
-  cat->reverse_variable_map = pool_calloc (cat->pool,
-					   cat->n_cats_total - cat->n_vars,
-					   sizeof *cat->reverse_variable_map);
-  
-  for (v = 0 ; v < cat->n_vp; ++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)
     {
-      int i;
-      struct var_params *vp = &cat->vp[v];
-      int n_cats_total = categoricals_n_count (cat, v);
-      struct hmap_node *node ;
+      struct interact_params *iap = &cat->iap[i];
+      const struct interaction *iact = iap->iact;
+
+      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);
+
+          iap->df_prod *= n_vals - 1;
+          iap->n_cats *= n_vals;
+        }
+
+      if (iact->n_vars > 0)
+        cat->df_sum += iap->df_prod;
+      cat->n_cats_total += iap->n_cats;
+    }
 
-      vp->reverse_value_map = pool_calloc (cat->pool, n_cats_total, sizeof *vp->reverse_value_map);
 
-      vp->base_subscript = idx;
+  cat->df_to_iact = pool_calloc (cat->pool, cat->df_sum,
+                                 sizeof *cat->df_to_iact);
 
-      for (node = hmap_first (&vp->map); node; node = hmap_next (&vp->map, node))
-	{
-	  const struct value_node *vn = HMAP_DATA (node, struct value_node, node);
-	  vp->reverse_value_map[vn->subscript] = vn;
-	}
+  cat->cat_to_iact = pool_calloc (cat->pool, cat->n_cats_total,
+                                  sizeof *cat->cat_to_iact);
 
-      /* Populate the reverse variable map.
-	 This implementation considers the first value of each categorical variable
-	 as the basis.  Therefore, this loop starts from 1 instead of 0 */
-      for (i = 1; i < vp->n_cats; ++i)
-	cat->reverse_variable_map[idx++] = v;
+  int idx_df = 0;
+  int idx_cat = 0;
+  for (int i = 0; i < cat->n_iap; ++i)
+    {
+      struct interact_params *iap = &cat->iap[i];
+
+      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->ivs[x++] = ivn;
+      sort (iap->ivs, x, sizeof *iap->ivs,
+            compare_interaction_value_3way, iap);
+
+      /* 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 (int j = 0; j < iap->n_cats; ++j)
+        cat->cat_to_iact[idx_cat++] = i;
     }
 
-  assert (cat->n_vars <= cat->n_vp);
-}
+  categoricals_dump (cat);
 
+  /* 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;
+
+      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);
+        }
+    }
 
-static int
-reverse_variable_lookup (const struct categoricals *cat, int subscript)
+  cat->sane = true;
+}
+
+union value *
+categoricals_get_var_values (const struct categoricals *cat,
+                             const struct variable *var, size_t *np)
 {
-  assert (cat->reverse_variable_map);
-  assert (subscript >= 0);
-  assert (subscript < cat->n_cats_total - cat->n_vars);
+  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);
 
-  return cat->reverse_variable_map[subscript];
+      struct value_node *valnd;
+      HMAP_FOR_EACH (valnd, struct value_node, node, &vn->valmap)
+        vn->values[valnd->index] = valnd->val;
+    }
+  return vn->values;
 }
 
-
-/* Return the categorical variable corresponding to SUBSCRIPT */
-const struct variable *
-categoricals_get_variable_by_subscript (const struct categoricals *cat, int subscript)
+static struct interact_params *
+df_to_iap (const struct categoricals *cat, int subscript)
 {
-  int index = reverse_variable_lookup (cat, subscript);
+  assert (subscript >= 0);
+  assert (subscript < cat->df_sum);
 
-  return cat->vp[index].var;
+  return &cat->iap[cat->df_to_iact[subscript]];
 }
 
-/* Return the value corresponding to SUBSCRIPT */
-const union value *
-categoricals_get_value_by_subscript (const struct categoricals *cat, int subscript)
+static struct interact_params *
+cat_index_to_iap (const struct categoricals *cat, int cat_index)
 {
-  int vindex = reverse_variable_lookup (cat, subscript);
-  const struct var_params *vp = &cat->vp[vindex];
-  const struct value_node *vn = vp->reverse_value_map [subscript - vp->base_subscript];
+  assert (cat_index >= 0);
+  assert (cat_index < cat->n_cats_total);
 
-  return &vn->value;
+  return &cat->iap[cat->cat_to_iact[cat_index]];
 }
 
+/* Return the interaction corresponding to SUBSCRIPT. */
+const struct interaction *
+categoricals_get_interaction_by_subscript (const struct categoricals *cat,
+                                           int subscript)
+{
+  return df_to_iap (cat, subscript)->iact;
+}
 
 double
-categoricals_get_weight_by_subscript (const struct categoricals *cat, int subscript)
+categoricals_get_weight_by_subscript (const struct categoricals *cat,
+                                      int subscript)
 {
-  int vindex = reverse_variable_lookup (cat, subscript);
-  const struct var_params *vp = &cat->vp[vindex];
-
-  return vp->cc;
+  return df_to_iap (cat, subscript)->cc;
 }
 
 double
-categoricals_get_sum_by_subscript (const struct categoricals *cat, int subscript)
+categoricals_get_sum_by_subscript (const struct categoricals *cat,
+                                   int subscript)
 {
-  int vindex = reverse_variable_lookup (cat, subscript);
-  const struct var_params *vp = &cat->vp[vindex];
-
-  const struct value_node *vn = vp->reverse_value_map [subscript - vp->base_subscript];
-  return vn->cc;
+  const struct interact_params *iap = df_to_iap (cat, subscript);
+  return iap->enc_sum[subscript - iap->base_df];
 }
 
 
 /* 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)
+{
+  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 int df = hmap_count (&iap->varnodes[v]->valmap) - 1;
+      const int dfpn = dfp * df;
+
+      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 result;
+}
+
+
+/* Returns unity if the value in case C at SUBSCRIPT is equal to the category
+   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 variable *var = categoricals_get_variable_by_subscript (cat, subscript);
-  int width = var_get_width (var);
+  return categoricals_get_code_for_case (cat, subscript, c, false);
+}
 
-  const union value *val = case_data (c, var);
+/* 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 value_equal (val, categoricals_get_value_by_subscript (cat, subscript), width);
+/* 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)
+{
+  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 CAT_INDEX. */
+const struct ccase *
+categoricals_get_case_by_category (const struct categoricals *cat,
+                                   int cat_index)
+{
+  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 cat_index)
+{
+  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)
 {
-  return cat->n_vars;
+  cat->payload = p;
+  cat->aux1 = aux1;
+  cat->aux2 = aux2;
 }