+++ /dev/null
-/* PSPP - a program for statistical analysis.
- Copyright (C) 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/>. */
-
-/*
- An interaction is a structure containing a "product" of other
- variables. The variables can be either categorical or numeric.
- If the variables are all numeric, the interaction is just the
- scalar product. If any of the variables are categorical, their
- product is a vector containing 0's in all but one entry. This entry
- is found by combining the vectors corresponding to the variables'
- OBS_VALS member. If there are K categorical variables, each with
- N_1, N_2, ..., N_K categories, then the interaction will have
- N_1 * N_2 * N_3 *...* N_K - 1 entries.
-
- When using these functions, make sure the orders of variables and
- values match when appropriate.
- */
-
-#include <config.h>
-#include <assert.h>
-#include <data/dictionary.h>
-#include <data/value.h>
-#include <data/variable.h>
-#include <gl/unistr.h>
-#include <math/interaction.h>
-#include <string.h>
-#include <xalloc.h>
-
-struct interaction_variable
-{
- int n_vars;
- const struct variable **members;
- struct variable *intr;
- size_t n_alpha;
-};
-
-struct interaction_value
-{
- const struct interaction_variable *intr;
- union value val; /* Concatenation of the string values in this
- interaction's value, or the product of a bunch
- of numeric values for a purely numeric
- interaction.
- */
- double f; /* Product of the numerical values in this interaction's value. */
-};
-
-/*
- An interaction_variable has type alpha if any of members have type
- alpha. Otherwise, its type is numeric.
- */
-struct interaction_variable *
-interaction_variable_create (const struct variable **vars, int n_vars)
-{
- struct interaction_variable *result = NULL;
- size_t i;
-
- if (n_vars > 0)
- {
- int width = 0;
-
- result = xmalloc (sizeof (*result));
- result->n_alpha = 0;
- result->members = xnmalloc (n_vars, sizeof (*result->members));
- result->n_vars = n_vars;
- for (i = 0; i < n_vars; i++)
- {
- result->members[i] = vars[i];
- if (var_is_alpha (vars[i]))
- {
- result->n_alpha++;
- width += var_get_width (vars[i]);
- }
- }
- result->intr = dict_create_internal_var (0, width);
- }
-
- return result;
-}
-void interaction_variable_destroy (struct interaction_variable *iv)
-{
- dict_destroy_internal_var (iv->intr);
- free (iv->members);
- free (iv);
-}
-
-/*
- Get one of the member variables.
- */
-const struct variable *
-interaction_get_member (const struct interaction_variable *iv, size_t i)
-{
- return iv->members[i];
-}
-
-size_t
-interaction_get_n_vars (const struct interaction_variable *iv)
-{
- return (iv == NULL) ? 0 : iv->n_vars;
-}
-
-size_t
-interaction_get_n_alpha (const struct interaction_variable *iv)
-{
- return iv->n_alpha;
-}
-
-size_t
-interaction_get_n_numeric (const struct interaction_variable *iv)
-{
- return (interaction_get_n_vars (iv) - interaction_get_n_alpha (iv));
-}
-
-/*
- Get the interaction variable itself.
- */
-const struct variable *
-interaction_get_variable (const struct interaction_variable *iv)
-{
- return iv->intr;
-}
-/*
- Given list of values, compute the value of the corresponding
- interaction. This "value" is not stored as the typical vector of
- 0's and one double, but rather the string values are concatenated to
- make one big string value, and the numerical values are multiplied
- together to give the non-zero entry of the corresponding vector.
- */
-struct interaction_value *
-interaction_value_create (const struct interaction_variable *var, const union value **vals)
-{
- struct interaction_value *result = NULL;
-
- if (var != NULL)
- {
- size_t i;
- int val_width = var_get_width (interaction_get_variable (var));
- int offset = 0;
- size_t n_vars = interaction_get_n_vars (var);
-
- result = xmalloc (sizeof (*result));
- result->intr = var;
-
- value_init (&result->val, val_width);
-
- result->f = 1.0;
- for (i = 0; i < n_vars; i++)
- {
- const struct variable *member = interaction_get_member (var, i);
-
- if (var_is_value_missing (member, vals[i], MV_ANY))
- {
- value_set_missing (&result->val, val_width);
- result->f = SYSMIS;
- break;
- }
- else
- {
- if (var_is_alpha (var->members[i]))
- {
- uint8_t *val = value_str_rw (&result->val, val_width);
- int w = var_get_width (var->members[i]);
- u8_cpy (val + offset, value_str (vals[i], w), w);
- offset += w;
- }
- else if (var_is_numeric (var->members[i]))
- {
- result->f *= vals[i]->f;
- }
- }
- }
- if (interaction_get_n_alpha (var) == 0)
- {
- /*
- If there are no categorical variables, then the
- interaction consists of only numeric data. In this case,
- code that uses this interaction_value will see the union
- member as the numeric value. If we were to store that
- numeric value in result->f as well, the calling code may
- inadvertently square this value by multiplying by
- result->val->f. Such multiplication would be correct for an
- interaction consisting of both categorical and numeric
- data, but a mistake for purely numerical interactions. To
- avoid the error, we set result->f to 1.0 for numeric
- interactions.
- */
- result->val.f = result->f;
- result->f = 1.0;
- }
- }
- return result;
-}
-
-const union value *
-interaction_value_get (const struct interaction_value *val)
-{
- return &val->val;
-}
-
-/*
- Returns the numeric value of the non-zero entry for the vector
- corresponding to this interaction. Do not use this function to get
- the numeric value of a purely numeric interaction. Instead, use the
- union value * returned by interaction_value_get.
- */
-double
-interaction_value_get_nonzero_entry (const struct interaction_value *val)
-{
- if (val != NULL)
- return val->f;
- return 1.0;
-}
-
-void
-interaction_value_destroy (struct interaction_value *val)
-{
- if (val != NULL)
- {
- int val_width = var_get_width (interaction_get_variable (val->intr));
-
- value_destroy (&val->val, val_width);
- free (val);
- }
-}
-
-/*
- Return a value from a variable that is an interaction.
- */
-struct interaction_value *
-interaction_case_data (const struct ccase *ccase, const struct interaction_variable *iv)
-{
- size_t i;
- size_t n_vars;
- const struct variable *member;
- const union value **vals = NULL;
-
- n_vars = interaction_get_n_vars (iv);
- vals = xnmalloc (n_vars, sizeof (*vals));
-
- for (i = 0; i < n_vars; i++)
- {
- member = interaction_get_member (iv, i);
- vals[i] = case_data (ccase, member);
- }
-
- return interaction_value_create (iv, vals);
-}
-
-bool
-is_interaction (const struct variable *var, const struct interaction_variable **iv, size_t n_intr)
-{
- size_t i;
- const struct variable *intr;
-
- for (i = 0; i < n_intr; i++)
- {
- intr = interaction_get_variable (iv[i]);
- if (intr == var)
- {
- return true;
- }
- }
- return false;
-}
-
+++ /dev/null
-/* PSPP - a program for statistical analysis.
- Copyright (C) 2009 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/>. */
-
-#ifndef INTERACTION_H
-#define INTERACTION_H
-#include <data/case.h>
-
-struct interaction_variable;
-struct interaction_value;
-
-struct interaction_variable * interaction_variable_create (const struct variable **, int);
-void interaction_variable_destroy (struct interaction_variable *);
-struct interaction_value * interaction_value_create (const struct interaction_variable *, const union value **);
-void interaction_value_destroy (struct interaction_value *);
-size_t interaction_variable_get_n_vars (const struct interaction_variable *);
-double interaction_value_get_nonzero_entry (const struct interaction_value *);
-const union value *interaction_value_get (const struct interaction_value *);
-const struct variable * interaction_get_variable (const struct interaction_variable *);
-size_t interaction_get_n_numeric (const struct interaction_variable *);
-size_t interaction_get_n_alpha (const struct interaction_variable *);
-size_t interaction_get_n_vars (const struct interaction_variable *);
-const struct variable * interaction_get_member (const struct interaction_variable *, size_t);
-bool is_interaction (const struct variable *, const struct interaction_variable **, size_t);
-struct interaction_value *
-interaction_case_data (const struct ccase *, const struct interaction_variable *);
-double interaction_value_get_nonzero_entry (const struct interaction_value *);
-#endif
projects / pspp-builds.git / commitdiff