/* PSPP - a program for statistical analysis.
- Copyright (C) 2009 Free Software Foundation, Inc.
+ Copyright (C) 2011, 2012 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
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 gsl_vector 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.
+#include <config.h>
- When using these functions, make sure the orders of variables and
- values match when appropriate.
- */
+#include "data/case.h"
+#include "interaction.h"
-#include <config.h>
-#include <assert.h>
-#include <gsl/gsl_math.h>
-#include <gsl/gsl_vector.h>
-#include <data/value.h>
-#include <data/variable.h>
-#include <math/interaction.h>
-#include <string.h>
-#include <xalloc.h>
+#include "data/value.h"
+#include "data/variable.h"
+#include "libpspp/str.h"
-struct interaction_variable
-{
- int n_vars;
- const struct variable **members;
- struct variable *intr;
- size_t n_alpha;
-};
+#include "gl/xalloc.h"
-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. */
-};
+#include <stdio.h>
-/*
- 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)
+/* Creates and returns an interaction. If V is nonnull, then the interaction
+ initially contains V, otherwise it is initially empty. */
+struct interaction *
+interaction_create (const struct variable *v)
{
- struct interaction_variable *result = NULL;
- size_t i;
-
- if (n_vars > 0)
+ struct interaction *iact = xmalloc (sizeof *iact);
+ iact->vars = xmalloc (sizeof *iact->vars);
+ iact->n_vars = 0;
+ if (v)
{
- result = xmalloc (sizeof (*result));
- result->n_alpha = 0;
- result->members = xnmalloc (n_vars, sizeof (*result->members));
- result->intr = var_create_internal (0);
- 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++;
- }
- }
+ iact->vars[0] = v;
+ iact->n_vars = 1;
}
- /*
- VAR_SET_WIDTH sets the type of the variable.
- */
- var_set_width (result->intr, MAX_SHORT_STRING * result->n_alpha + 1);
-
- return result;
+ return iact;
}
-void interaction_variable_destroy (struct interaction_variable *iv)
+
+/* Returns a (deep) copy of interaction SRC. */
+struct interaction *
+interaction_clone (const struct interaction *src)
{
- var_destroy (iv->intr);
- free (iv->members);
- free (iv);
+ struct interaction *dst = xmalloc (sizeof *dst);
+ dst->vars = xmemdup (src->vars, src->n_vars * sizeof *src->vars);
+ dst->n_vars = src->n_vars;
+ return dst;
}
-/*
- Get one of the member variables.
- */
-const struct variable *
-interaction_variable_get_member (const struct interaction_variable *iv, size_t i)
+/* Frees IACT. */
+void
+interaction_destroy (struct interaction *iact)
{
- return iv->members[i];
+ if (iact)
+ {
+ free (iact->vars);
+ free (iact);
+ }
}
-size_t
-interaction_get_n_vars (const struct interaction_variable *iv)
+/* Appends variable V to IACT.
+
+ V must not already be in IACT. */
+void
+interaction_add_variable (struct interaction *iact, const struct variable *v)
{
- return (iv == NULL) ? 0 : iv->n_vars;
+ iact->vars = xrealloc (iact->vars, (iact->n_vars + 1) * sizeof *iact->vars);
+ iact->vars[iact->n_vars++] = v;
}
-size_t
-interaction_get_n_alpha (const struct interaction_variable *iv)
+/* Returns true iff the variables in X->VARS are a proper subset of the
+ variables in Y->VARS. */
+bool
+interaction_is_proper_subset (const struct interaction *x,
+ const struct interaction *y)
{
- return iv->n_alpha;
+ return x->n_vars >= y->n_vars && interaction_is_subset (x, y);
}
-size_t
-interaction_get_n_numeric (const struct interaction_variable *iv)
+static bool
+interaction_contains (const struct interaction *iact, const struct variable *v)
{
- return (interaction_get_n_vars (iv) - interaction_get_n_alpha (iv));
+ for (size_t i = 0; i < iact->n_vars; i++)
+ if (iact->vars[i] == v)
+ return true;
+ return false;
}
-/*
- Get the interaction varibale itself.
- */
-const struct variable *
-interaction_variable_get_var (const struct interaction_variable *iv)
+/* Returns true iff the variables in X->VARS are a subset (proper or otherwise)
+ of the variables in Y->VARS. */
+bool
+interaction_is_subset (const struct interaction *x,
+ const struct interaction *y)
{
- return iv->intr;
+ if (x->n_vars > y->n_vars)
+ return false;
+
+ for (size_t i = 0; i < x->n_vars; i++)
+ if (!interaction_contains (y, x->vars[i]))
+ return false;
+
+ return true;
}
-/*
- 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)
+
+/* Prints the variables in IACT on stdout, for debugging purposes. */
+void
+interaction_dump (const struct interaction *iact)
{
- struct interaction_value *result = NULL;
- const struct variable *member;
- size_t i;
- size_t n_vars;
-
- if (var != NULL)
+ if (iact->n_vars == 0)
+ printf ("(empty)\n");
+ else
{
- result = xmalloc (sizeof (*result));
- result->intr = var;
- n_vars = interaction_get_n_vars (var);
- result->val = value_create (n_vars * MAX_SHORT_STRING + 1);
- result->f = 1.0;
- for (i = 0; i < n_vars; i++)
- {
- member = interaction_variable_get_member (var, i);
-
- if (var_is_value_missing (member, vals[i], MV_ANY))
- {
- value_set_missing (result->val, MAX_SHORT_STRING);
- result->f = SYSMIS;
- break;
- }
- else
- {
- if (var_is_alpha (var->members[i]))
- {
- strncat (result->val->s, vals[i]->s, MAX_SHORT_STRING);
- }
- 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;
- }
+ for (size_t v = 0; v < iact->n_vars; ++v)
+ {
+ printf ("%s", var_get_name (iact->vars[v]));
+ if (v + 1 < iact->n_vars)
+ printf (" * ");
+ }
+ printf ("\n");
}
- return result;
}
-union value *
-interaction_value_get (const struct interaction_value *val)
-{
- return val->val;
-}
+/* Appends STR with a representation of the interaction, suitable for user
+ display.
-/*
- 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 purley numeric interaction. Instead, use the
- union value * returned by interaction_value_get.
- */
-double
-interaction_value_get_nonzero_entry (const struct interaction_value *val)
+ STR must have been initialised prior to calling this function. */
+void
+interaction_to_string (const struct interaction *iact, struct string *str)
{
- if (val != NULL)
- return val->f;
- return 1.0;
+ for (size_t v = 0; v < iact->n_vars; ++v)
+ {
+ ds_put_cstr (str, var_to_string (iact->vars[v]));
+ if (v + 1 < iact->n_vars)
+ ds_put_cstr (str, " × ");
+ }
}
-void
-interaction_value_destroy (struct interaction_value *val)
+/* Returns a hash of the values in C given by variables in IACT, using BASE as
+ a basis for the hash. */
+unsigned int
+interaction_case_hash (const struct interaction *iact,
+ const struct ccase *c, unsigned int base)
{
- if (val != NULL)
+ size_t hash = base;
+ for (size_t i = 0; i < iact->n_vars; ++i)
{
- free (val->val);
- free (val);
+ const struct variable *var = iact->vars[i];
+ const union value *val = case_data (c, var);
+ hash = value_hash (val, var_get_width (var), hash);
}
+ return hash;
}
-/*
- Return a value from a variable that is an interaction.
- */
-struct interaction_value *
-interaction_case_data (const struct ccase *ccase, const struct variable *var,
- const struct interaction_variable **intr_vars, size_t n_intr)
+/* Returns true iff all the variables in IACT have equal values in C1 and
+ C2. */
+bool
+interaction_case_equal (const struct interaction *iact,
+ const struct ccase *c1, const struct ccase *c2)
{
- size_t i;
- size_t n_vars;
- const struct interaction_variable *iv;
- const struct variable *intr;
- const struct variable *member;
- const union value **vals = NULL;
-
- for (i = 0; i < n_intr; i++)
+ for (size_t i = 0; i < iact->n_vars; ++i)
{
- iv = intr_vars[i];
- intr = interaction_variable_get_var (iv);
- if (var_get_dict_index (intr) == var_get_dict_index (var))
- {
- break;
- }
+ const struct variable *var = iact->vars[i];
+ if (!value_equal (case_data (c1, var), case_data (c2, var),
+ var_get_width (var)))
+ return false;
}
- n_vars = interaction_get_n_vars (iv);
- vals = xnmalloc (n_vars, sizeof (*vals));
- for (i = 0; i < n_vars; i++)
+
+ return true;
+}
+
+/* Returns a strcmp()-like comparison result for the variables in IACT and
+ their values in C1 and C2. */
+int
+interaction_case_cmp_3way (const struct interaction *iact,
+ const struct ccase *c1, const struct ccase *c2)
+{
+ for (size_t i = 0; i < iact->n_vars; ++i)
{
- member = interaction_variable_get_member (iv, i);
- vals[i] = case_data (ccase, member);
+ const struct variable *var = iact->vars[i];
+ int cmp = value_compare_3way (case_data (c1, var), case_data (c2, var),
+ var_get_width (var));
+ if (cmp)
+ return cmp;
}
- return interaction_value_create (iv, vals);
+
+ return 0;
}
+/* Returns true iff any of the variables in IACT have a missing value in C,
+ using EXCLUDE to decide which kinds of missing values to count. */
bool
-is_interaction (const struct variable *var, const struct interaction_variable **iv, size_t n_intr)
+interaction_case_is_missing (const struct interaction *iact,
+ const struct ccase *c, enum mv_class exclude)
{
- size_t i;
- const struct variable *intr;
-
- for (i = 0; i < n_intr; i++)
- {
- intr = interaction_variable_get_var (iv[i]);
- if (var_get_dict_index (intr) == var_get_dict_index (var))
- {
- return true;
- }
- }
+ for (size_t i = 0; i < iact->n_vars; ++i)
+ if (var_is_value_missing (iact->vars[i], case_data (c, iact->vars[i]))
+ & exclude)
+ return true;
+
return false;
}
-
+
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