/* wavelet/haar.c

 * 

 * Copyright (C) 2004 Ivo Alxneit

 * 

 * 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, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 */

#include <config.h>

#include <gsl/gsl_errno.h>

#include <gsl/gsl_math.h>

#include <gsl/gsl_wavelet.h>

static const double ch_2[2] = { M_SQRT1_2, M_SQRT1_2 };

static const double cg_2[2] = { M_SQRT1_2, -(M_SQRT1_2) };

static int

haar_init (const double **h1, const double **g1, const double **h2,

           const double **g2, size_t * nc, size_t * offset,

           const size_t member)

{

  if (member != 2)

    {

      return GSL_FAILURE;

    }

  *h1 = ch_2;

  *g1 = cg_2;

  *h2 = ch_2;

  *g2 = cg_2;

  *nc = 2;

  *offset = 0;

  return GSL_SUCCESS;

}

static int

haar_centered_init (const double **h1, const double **g1, const double **h2,

                    const double **g2, size_t * nc, size_t * offset,

                    const size_t member)

{

  if (member != 2)

    {

      return GSL_FAILURE;

    }

  *h1 = ch_2;

  *g1 = cg_2;

  *h2 = ch_2;

  *g2 = cg_2;

  *nc = 2;

  *offset = 1;

  return GSL_SUCCESS;

}

static const gsl_wavelet_type haar_type = {

  "haar",

  &haar_init

};

static const gsl_wavelet_type haar_centered_type = {

  "haar-centered",

  &haar_centered_init

};

const gsl_wavelet_type *gsl_wavelet_haar = &haar_type;

const gsl_wavelet_type *gsl_wavelet_haar_centered = &haar_centered_type;