-/* PSPP - a program for statistical analysis.
- Copyright (C) 2005, 2009, 2010 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
- the Free Software Foundation, either version 3 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, see <http://www.gnu.org/licenses/>. */
-
-/*
- Accessor functions for matching coefficients and variables.
- */
-#include <config.h>
-#include <math/coefficient.h>
-#include "src/math/design-matrix.h"
-
-#include <gl/xalloc.h>
-
-
-struct varinfo
-{
- const struct variable *v; /* Variable associated with this
- coefficient. Note this variable
- may not be unique. In other words,
- a coefficient structure may have
- other v_info's, each with its own
- variable. */
- const union value *val; /* Value of the variable v which this varinfo
- refers to. This member is relevant only to
- categorical variables. */
- double mean; /* Mean for this variable */
- double sd; /* Standard deviation for this variable */
-};
-
-void
-pspp_coeff_free (struct pspp_coeff *c)
-{
- free (c->v_info);
- free (c);
-}
-
-/*
- Initialize the variable and value pointers inside the
- coefficient structures for the model.
- */
-void
-pspp_coeff_init (struct pspp_coeff ** coeff, const struct design_matrix *X)
-{
- size_t i;
- int n_vals = 1;
-
- assert (coeff != NULL);
- for (i = 0; i < X->m->size2; i++)
- {
- coeff[i] = xmalloc (sizeof (*coeff[i]));
- coeff[i]->n_vars = n_vals; /* Currently, no procedures allow
- interactions. This line will have to
- change when procedures that allow
- interaction terms are written.
- */
- coeff[i]->v_info = xnmalloc (coeff[i]->n_vars, sizeof (*coeff[i]->v_info));
- assert (coeff[i]->v_info != NULL);
- coeff[i]->v_info->v = design_matrix_col_to_var (X, i);
-
- if (var_is_alpha (coeff[i]->v_info->v))
- {
- size_t k;
- k = design_matrix_var_to_column (X, coeff[i]->v_info->v);
- assert (k <= i);
- k = i - k;
- coeff[i]->v_info->val =
- cat_subscript_to_value (k, coeff[i]->v_info->v);
- }
- coeff[i]->v_info->mean = 0.0;
- coeff[i]->v_info->sd = 0.0;
- }
-}
-void
-pspp_coeff_set_estimate (struct pspp_coeff *coef, double estimate)
-{
- coef->estimate = estimate;
-}
-
-void
-pspp_coeff_set_std_err (struct pspp_coeff *coef, double std_err)
-{
- coef->std_err = std_err;
-}
-
-/*
- Return the estimated value of the coefficient.
- */
-double
-pspp_coeff_get_est (const struct pspp_coeff *coef)
-{
- if (coef == NULL)
- {
- return 0.0;
- }
- return coef->estimate;
-}
-
-/*
- Return the standard error of the estimated coefficient.
-*/
-double
-pspp_coeff_get_std_err (const struct pspp_coeff *coef)
-{
- if (coef == NULL)
- {
- return 0.0;
- }
- return coef->std_err;
-}
-
-/*
- How many variables are associated with this coefficient?
- */
-int
-pspp_coeff_get_n_vars (struct pspp_coeff *coef)
-{
- if (coef == NULL)
- {
- return 0;
- }
- return coef->n_vars;
-}
-
-/*
- Which variable does this coefficient match? I should be
- 0 unless the coefficient refers to an interaction term.
- */
-const struct variable *
-pspp_coeff_get_var (struct pspp_coeff *coef, int i)
-{
- if (coef == NULL)
- {
- return NULL;
- }
- assert (i < coef->n_vars);
- return (coef->v_info + i)->v;
-}
-
-/*
- Which coefficient does this variable match? If the variable is
- categorical, and has more than one coefficient, use the VAL to find
- its coefficient.
- */
-struct pspp_coeff *
-pspp_coeff_var_to_coeff (const struct variable *v, struct pspp_coeff **coefs,
- size_t n_coef, const union value *val)
-{
- size_t i = 0;
- size_t j = 0;
-
- struct pspp_coeff *result = NULL;
-
- if (v != NULL)
- {
- while (i < n_coef)
- {
- if (coefs[i]->v_info != NULL)
- {
- if (coefs[i]->v_info->v == v)
- {
- break;
- }
- }
- i++;
- }
- result = coefs[i];
- if (var_is_alpha (v))
- {
- /*
- Use the VAL to find the coefficient.
- */
- if (val != NULL)
- {
- int width = var_get_width (v);
-
- j = i;
- while (j < n_coef
- && value_compare_3way (pspp_coeff_get_value (coefs[j], v),
- val, width) != 0)
- {
- j++;
- }
- result = ((j < n_coef) ? coefs[j] : NULL);
- }
- }
- }
- return result;
-}
-
-/*
- Which value is associated with this coefficient/variable combination?
- */
-const union value *
-pspp_coeff_get_value (struct pspp_coeff *coef,
- const struct variable *v)
-{
- int i = 0;
- const struct variable *candidate;
-
- if (coef == NULL || v == NULL)
- {
- return NULL;
- }
- if (var_is_numeric (v))
- {
- return NULL;
- }
- while (i < coef->n_vars)
- {
- candidate = pspp_coeff_get_var (coef, i);
- if (v == candidate)
- {
- return (coef->v_info + i)->val;
- }
- i++;
- }
- return NULL;
-}
-
-/*
- Get or set the standard deviation of the variable associated with this coefficient.
- */
-double pspp_coeff_get_sd (const struct pspp_coeff *coef)
-{
- return coef->v_info->sd;
-}
-void pspp_coeff_set_sd (struct pspp_coeff *coef, double s)
-{
- coef->v_info->sd = s;
-}
-
-/*
- Get or set the mean for the variable associated with this coefficient.
-*/
-double pspp_coeff_get_mean (const struct pspp_coeff *coef)
-{
- return coef->v_info->mean;
-}
-
-void pspp_coeff_set_mean (struct pspp_coeff *coef, double m)
-{
- coef->v_info->mean = m;
-}
-