+++ /dev/null
-/* PSPP - binary encodings for categorical variables.
- Copyright (C) 2005 Free Software Foundation, Inc.
- Written by Jason H Stover <jason@sakla.net>.
-
- 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 the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
-
- This program is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- 02110-1301, USA. */
-
-/*
- Functions and data structures to store values of a categorical
- variable, and to recode those values into binary vectors.
-
- For some statistical models, it is necessary to change each value
- of a categorical variable to a vector with binary entries. These
- vectors are then stored as sub-rows within a matrix during
- model-fitting. For example, we need functions and data strucutres to map a
- value, say 'a', of a variable named 'cat_var', to a vector, say (0
- 1 0 0 0), and vice versa. We also need to be able to map the
- vector back to the value 'a', and if the vector is a sub-row of a
- matrix, we need to know which sub-row corresponds to the variable
- 'cat_var'.
-*/
-#include <config.h>
-
-#include "category.h"
-
-#include <assert.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <libpspp/alloc.h>
-#include <libpspp/message.h>
-#include "category.h"
-#include "value.h"
-#include "variable.h"
-
-#define CAT_VALUE_NOT_FOUND -2
-
-#define N_INITIAL_CATEGORIES 1
-
-/*
- This structure contains the observed values of a
- categorical variable.
- */
-struct cat_vals
-{
- union value *vals;
- size_t n_categories;
- size_t n_allocated_categories; /* This is used only during
- initialization to keep
- track of the number of
- values stored.
- */
-};
-
-void
-cat_stored_values_create (const struct variable *v)
-{
- if (!var_has_obs_vals (v))
- {
- struct cat_vals *obs_vals = xmalloc (sizeof *obs_vals);
-
- obs_vals->n_categories = 0;
- obs_vals->n_allocated_categories = N_INITIAL_CATEGORIES;
- obs_vals->vals = xnmalloc (N_INITIAL_CATEGORIES, sizeof *obs_vals->vals);
- var_set_obs_vals (v, obs_vals);
- }
-}
-
-void
-cat_stored_values_destroy (struct cat_vals *obs_vals)
-{
- if (obs_vals != NULL)
- {
- if (obs_vals->n_allocated_categories > 0)
- free (obs_vals->vals);
- free (obs_vals);
- }
-}
-
-/*
- Which subscript corresponds to val?
- */
-size_t
-cat_value_find (const struct variable *v, const union value *val)
-{
- struct cat_vals *obs_vals = var_get_obs_vals (v);
- size_t i;
- const union value *candidate;
-
- for (i = 0; i < obs_vals->n_categories; i++)
- {
- candidate = obs_vals->vals + i;
- assert (candidate != NULL);
- if (!compare_values (candidate, val, var_get_width (v)))
- {
- return i;
- }
- }
- return CAT_VALUE_NOT_FOUND;
-}
-
-/*
- Add the new value unless it is already present.
- */
-void
-cat_value_update (const struct variable *v, const union value *val)
-{
- if (var_is_alpha (v))
- {
- struct cat_vals *cv = var_get_obs_vals (v);
- if (cat_value_find (v, val) == CAT_VALUE_NOT_FOUND)
- {
- if (cv->n_categories >= cv->n_allocated_categories)
- {
- cv->n_allocated_categories *= 2;
- cv->vals = xnrealloc (cv->vals,
- cv->n_allocated_categories,
- sizeof *cv->vals);
- }
- cv->vals[cv->n_categories] = *val;
- cv->n_categories++;
- }
- }
-}
-
-const union value *
-cat_subscript_to_value (const size_t s, const struct variable *v)
-{
- struct cat_vals *obs_vals = var_get_obs_vals (v);
- return s < obs_vals->n_categories ? obs_vals->vals + s : NULL;
-}
-
-/*
- Return the number of categories of a categorical variable.
- */
-size_t
-cat_get_n_categories (const struct variable *v)
-{
- return var_get_obs_vals (v)->n_categories;
-}
-