/* gsl_histogram2d_oper.c

 * Copyright (C) 2000  Simone Piccardi

 *

 * This library 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 library; if not, write to the Free Software Foundation, Inc.,

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

 */

/***************************************************************

 *

 * File gsl_histogram2d_oper.c: 

 * Routine to make operation on 2D histograms. 

 * Need GSL library and header.

 * Contains the routines:

 * gsl_histogram2d_same_binning check if two histograms have the same binning 

 * gsl_histogram2d_add          add two histogram

 * gsl_histogram2d_sub          subctract two histogram

 * gsl_histogram2d_mult         multiply two histogram

 * gsl_histogram2d_div          divide two histogram

 * gsl_histogram2d_scale        scale histogram contents

 *

 * Author: S. Piccardi

 * Jan. 2000

 *

 ***************************************************************/

#include <config.h>

#include <stdlib.h>

#include <gsl/gsl_errno.h>

#include <gsl/gsl_histogram2d.h>

/* 

 * gsl_histogram2d_same_binning:

 * control if two histogram have the

 * same binning

 */

int

gsl_histogram2d_equal_bins_p (const gsl_histogram2d * h1,

                              const gsl_histogram2d * h2)

{

  if ((h1->nx != h2->nx) || (h1->ny != h2->ny))

    {

      return 0;

    }

  {

    size_t i;

    /* init ranges */

    for (i = 0; i <= (h1->nx); i++)

      {

        if (h1->xrange[i] != h2->xrange[i])

          {

            return 0;

          }

      }

    for (i = 0; i <= (h1->ny); i++)

      {

        if (h1->yrange[i] != h2->yrange[i])

          {

            return 0;

          }

      }

  }

  return 1;

}

/* 

 * gsl_histogram2d_add:

 * add two histogram

 */

int 

gsl_histogram2d_add (gsl_histogram2d * h1, const gsl_histogram2d * h2)

{

  size_t i;

  if (!gsl_histogram2d_equal_bins_p (h1, h2))

    {

      GSL_ERROR ("histograms have different binning", GSL_EINVAL);

    }

  for (i = 0; i < (h1->nx) * (h1->ny); i++)

    {

      h1->bin[i] += h2->bin[i];

    }

  return GSL_SUCCESS;

}

/* 

 * gsl_histogram2d_sub:

 * subtract two histogram

 */

int 

gsl_histogram2d_sub (gsl_histogram2d * h1, const gsl_histogram2d * h2)

{

  size_t i;

  if (!gsl_histogram2d_equal_bins_p (h1, h2))

    {

      GSL_ERROR ("histograms have different binning", GSL_EINVAL);

    }

  for (i = 0; i < (h1->nx) * (h1->ny); i++)

    {

      h1->bin[i] -= h2->bin[i];

    }

  return GSL_SUCCESS;

}

/* 

 * gsl_histogram2d_mult:

 * multiply two histogram

 */

int 

gsl_histogram2d_mul (gsl_histogram2d * h1, const gsl_histogram2d * h2)

{

  size_t i;

  if (!gsl_histogram2d_equal_bins_p (h1, h2))

    {

      GSL_ERROR ("histograms have different binning", GSL_EINVAL);

    }

  for (i = 0; i < (h1->nx) * (h1->ny); i++)

    {

      h1->bin[i] *= h2->bin[i];

    }

  return GSL_SUCCESS;

}

/* 

 * gsl_histogram2d_div:

 * divide two histogram

 */

int 

gsl_histogram2d_div (gsl_histogram2d * h1, const gsl_histogram2d * h2)

{

  size_t i;

  if (!gsl_histogram2d_equal_bins_p (h1, h2))

    {

      GSL_ERROR ("histograms have different binning", GSL_EINVAL);

    }

  for (i = 0; i < (h1->nx) * (h1->ny); i++)

    {

      h1->bin[i] /= h2->bin[i];

    }

  return GSL_SUCCESS;

}

/* 

 * gsl_histogram2d_scale:

 * scale a histogram by a numeric factor

 */

int 

gsl_histogram2d_scale (gsl_histogram2d * h, double scale)

{

  size_t i;

  for (i = 0; i < (h->nx) * (h->ny); i++)

    {

      h->bin[i] *= scale;

    }

  return GSL_SUCCESS;

}

/* 

 * gsl_histogram2d_shift:

 * shift a histogram by a numeric offset

 */

int 

gsl_histogram2d_shift (gsl_histogram2d * h, double shift)

{

  size_t i;

  for (i = 0; i < (h->nx) * (h->ny); i++)

    {

      h->bin[i] += shift;

    }

  return GSL_SUCCESS;

}