/* PSPP - a program for statistical analysis.
   Copyright (C) 2008 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/>. */

/*
  Create covariance matrices for procedures that need them.
 */

#ifndef COVARIANCE_MATRIX_H
#define COVARIANCE_MATRIX_H

#include <math/design-matrix.h>
#include <math/interaction.h>

struct moments1;
struct ccase;
struct hsh_table;
struct covariance_matrix;
enum
{ ONE_PASS,
  TWO_PASS
};

/*
  How to deal with missing values.
 */
enum
{ LISTWISE,
  PAIRWISE
};
struct design_matrix *covariance_matrix_create (size_t, const struct variable *[]);

void covariance_matrix_destroy (struct covariance_matrix *);
void covariance_pass_two (struct design_matrix *, double,
			  double, double, const struct variable *,
			  const struct variable *, const union value *,
			  const union value *);
void covariance_matrix_compute (struct covariance_matrix *);
struct covariance_matrix *covariance_matrix_init (size_t,
						  const struct variable *[],
						  int, int, enum mv_class);
void covariance_matrix_free (struct covariance_matrix *);
void covariance_matrix_accumulate (struct covariance_matrix *,
				   const struct ccase *, void **, size_t);
struct design_matrix *covariance_to_design (const struct covariance_matrix *);
double covariance_matrix_get_element (const struct covariance_matrix *, size_t, size_t);
void covariance_interaction_set (struct covariance_matrix *, 
				 const struct interaction_variable **, size_t);
#endif