--- /dev/null
+/* PSPP - Creates design-matrices.
+ 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. */
+
+/*
+ Create design matrices for procedures that need them.
+*/
+#include <config.h>
+#include <stdlib.h>
+#include <message.h>
+#include "alloc.h"
+#include "message.h"
+#include "variable.h"
+#include "category.h"
+#include "design-matrix.h"
+#include <string.h>
+#include <math.h>
+#include <gsl/gsl_machine.h>
+#include <gsl/gsl_vector.h>
+#include <gsl/gsl_matrix.h>
+
+#define DM_COLUMN_NOT_FOUND -1
+#define DM_INDEX_NOT_FOUND -3
+
+/*
+ Which element of a vector is equal to the value x?
+ */
+static size_t
+cat_which_element_eq (const gsl_vector * vec, double x)
+{
+ size_t i;
+
+ for (i = 0; i < vec->size; i++)
+ {
+ if (fabs (gsl_vector_get (vec, i) - x) < GSL_DBL_EPSILON)
+ {
+ return i;
+ }
+ }
+ return CAT_VALUE_NOT_FOUND;
+}
+static int
+cat_is_zero_vector (const gsl_vector * vec)
+{
+ size_t i;
+
+ for (i = 0; i < vec->size; i++)
+ {
+ if (gsl_vector_get (vec, i) != 0.0)
+ {
+ return 0;
+ }
+ }
+ return 1;
+}
+
+/*
+ Return the value of v corresponding to the vector vec.
+ */
+union value *
+cat_vector_to_value (const gsl_vector * vec, struct variable *v)
+{
+ size_t i;
+
+ i = cat_which_element_eq (vec, 1.0);
+ if (i != CAT_VALUE_NOT_FOUND)
+ {
+ return cat_subscript_to_value (i + 1, v);
+ }
+ if (cat_is_zero_vector (vec))
+ {
+ return cat_subscript_to_value (0, v);
+ }
+ return NULL;
+}
+
+struct design_matrix *
+design_matrix_create (int n_variables,
+ const struct variable *v_variables[],
+ const size_t n_data)
+{
+ struct design_matrix *dm;
+ const struct variable *v;
+ size_t i;
+ size_t n_cols = 0;
+ size_t col;
+
+ dm = xmalloc (sizeof *dm);
+ dm->vars = xnmalloc (n_variables, sizeof *dm->vars);
+ dm->n_vars = n_variables;
+
+ for (i = 0; i < n_variables; i++)
+ {
+ v = v_variables[i];
+ assert ((dm->vars + i) != NULL);
+ (dm->vars + i)->v = v; /* Allows us to look up the variable from
+ the design matrix. */
+ (dm->vars + i)->first_column = n_cols;
+ if (v->type == NUMERIC)
+ {
+ (dm->vars + i)->last_column = n_cols;
+ n_cols++;
+ }
+ else if (v->type == ALPHA)
+ {
+ assert (v->obs_vals != NULL);
+ (dm->vars + i)->last_column =
+ (dm->vars + i)->first_column + v->obs_vals->n_categories - 2;
+ n_cols += v->obs_vals->n_categories - 1;
+ }
+ }
+ dm->m = gsl_matrix_calloc (n_data, n_cols);
+ col = 0;
+
+ return dm;
+}
+
+void
+design_matrix_destroy (struct design_matrix *dm)
+{
+ free (dm->vars);
+ gsl_matrix_free (dm->m);
+ free (dm);
+}
+
+/*
+ Return the index of the variable for the
+ given column.
+ */
+static size_t
+design_matrix_col_to_var_index (const struct design_matrix *dm, size_t col)
+{
+ size_t i;
+ struct design_matrix_var v;
+
+ for (i = 0; i < dm->n_vars; i++)
+ {
+ v = dm->vars[i];
+ if (v.first_column <= col && col <= v.last_column)
+ return (v.v)->index;
+ }
+ return DM_INDEX_NOT_FOUND;
+}
+
+/*
+ Return a pointer to the variable whose values
+ are stored in column col.
+ */
+struct variable *
+design_matrix_col_to_var (const struct design_matrix *dm, size_t col)
+{
+ size_t index;
+ size_t i;
+ struct design_matrix_var dmv;
+
+ index = design_matrix_col_to_var_index (dm, col);
+ for (i = 0; i < dm->n_vars; i++)
+ {
+ dmv = dm->vars[i];
+ if ((dmv.v)->index == index)
+ {
+ return (struct variable *) dmv.v;
+ }
+ }
+ return NULL;
+}
+
+static size_t
+cmp_dm_var_index (const struct design_matrix_var *dmv, size_t index)
+{
+ if (dmv->v->index == index)
+ return 1;
+ return 0;
+}
+
+/*
+ Return the number of the first column which holds the
+ values for variable v.
+ */
+size_t
+design_matrix_var_to_column (const struct design_matrix * dm,
+ const struct variable * v)
+{
+ size_t i;
+ struct design_matrix_var tmp;
+
+ for (i = 0; i < dm->n_vars; i++)
+ {
+ tmp = dm->vars[i];
+ if (cmp_dm_var_index (&tmp, v->index))
+ {
+ return tmp.first_column;
+ }
+ }
+ return DM_COLUMN_NOT_FOUND;
+}
+
+/* Last column. */
+static size_t
+dm_var_to_last_column (const struct design_matrix *dm,
+ const struct variable *v)
+{
+ size_t i;
+ struct design_matrix_var tmp;
+
+ for (i = 0; i < dm->n_vars; i++)
+ {
+ tmp = dm->vars[i];
+ if (cmp_dm_var_index (&tmp, v->index))
+ {
+ return tmp.last_column;
+ }
+ }
+ return DM_COLUMN_NOT_FOUND;
+}
+
+/*
+ Set the appropriate value in the design matrix,
+ whether that value is from a categorical or numeric
+ variable. For a categorical variable, only the usual
+ binary encoding is allowed.
+ */
+void
+design_matrix_set_categorical (struct design_matrix *dm, size_t row,
+ const struct variable *var,
+ const union value *val)
+{
+ size_t col;
+ size_t is_one;
+ size_t fc;
+ size_t lc;
+ double entry;
+
+ assert (var->type == ALPHA);
+ fc = design_matrix_var_to_column (dm, var);
+ lc = dm_var_to_last_column (dm, var);
+ assert (lc != DM_COLUMN_NOT_FOUND);
+ assert (fc != DM_COLUMN_NOT_FOUND);
+ is_one = fc + cat_value_find (var, val);
+ for (col = fc; col <= lc; col++)
+ {
+ entry = (col == is_one) ? 1.0 : 0.0;
+ gsl_matrix_set (dm->m, row, col, entry);
+ }
+}
+void
+design_matrix_set_numeric (struct design_matrix *dm, size_t row,
+ const struct variable *var, const union value *val)
+{
+ size_t col;
+
+ assert (var->type == NUMERIC);
+ col = design_matrix_var_to_column ((const struct design_matrix *) dm, var);
+ assert (col != DM_COLUMN_NOT_FOUND);
+ gsl_matrix_set (dm->m, row, col, val->f);
+}
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