/* histogram/init2d.c

 * 

 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Brian Gough

 * 

 * 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 <stdlib.h>

#include <math.h>

#include <gsl/gsl_errno.h>

#include <gsl/gsl_histogram2d.h>

gsl_histogram2d *

gsl_histogram2d_alloc (const size_t nx, const size_t ny)

{

  gsl_histogram2d *h;

  if (nx == 0)

    {

      GSL_ERROR_VAL ("histogram2d length nx must be positive integer",

                        GSL_EDOM, 0);

    }

  if (ny == 0)

    {

      GSL_ERROR_VAL ("histogram2d length ny must be positive integer",

                        GSL_EDOM, 0);

    }

  h = (gsl_histogram2d *) malloc (sizeof (gsl_histogram2d));

  if (h == 0)

    {

      GSL_ERROR_VAL ("failed to allocate space for histogram2d struct",

                        GSL_ENOMEM, 0);

    }

  h->xrange = (double *) malloc ((nx + 1) * sizeof (double));

  if (h->xrange == 0)

    {

      free (h);         /* exception in constructor, avoid memory leak */

      GSL_ERROR_VAL ("failed to allocate space for histogram2d x ranges",

                        GSL_ENOMEM, 0);

    }

  h->yrange = (double *) malloc ((ny + 1) * sizeof (double));

  if (h->yrange == 0)

    {

      free (h->xrange);

      free (h);         /* exception in constructor, avoid memory leak */

      GSL_ERROR_VAL ("failed to allocate space for histogram2d y ranges",

                        GSL_ENOMEM, 0);

    }

  h->bin = (double *) malloc (nx * ny * sizeof (double));

  if (h->bin == 0)

    {

      free (h->xrange);

      free (h->yrange);

      free (h);         /* exception in constructor, avoid memory leak */

      GSL_ERROR_VAL ("failed to allocate space for histogram bins",

                        GSL_ENOMEM, 0);

    }

  h->nx = nx;

  h->ny = ny;

  return h;

}

static void

make_uniform (double range[], size_t n, double xmin, double xmax)

{

  size_t i;

  for (i = 0; i <= n; i++)

    {

      double f1 = ((double) (n-i) / (double) n);

      double f2 = ((double) i / (double) n);

      range[i] = f1 * xmin +  f2 * xmax;

    }

}

gsl_histogram2d *

gsl_histogram2d_calloc_uniform (const size_t nx, const size_t ny,

                                const double xmin, const double xmax,

                                const double ymin, const double ymax)

{

  gsl_histogram2d *h;

  if (xmin >= xmax)

    {

      GSL_ERROR_VAL ("xmin must be less than xmax", GSL_EINVAL, 0);

    }

  if (ymin >= ymax)

    {

      GSL_ERROR_VAL ("ymin must be less than ymax", GSL_EINVAL, 0);

    }

  h = gsl_histogram2d_calloc (nx, ny);

  if (h == 0)

    {

      return h;

    }

  make_uniform (h->xrange, nx, xmin, xmax);

  make_uniform (h->yrange, ny, ymin, ymax);

  return h;

}

gsl_histogram2d *

gsl_histogram2d_calloc (const size_t nx, const size_t ny)

{

  gsl_histogram2d *h;

  if (nx == 0)

    {

      GSL_ERROR_VAL ("histogram2d length nx must be positive integer",

                        GSL_EDOM, 0);

    }

  if (ny == 0)

    {

      GSL_ERROR_VAL ("histogram2d length ny must be positive integer",

                        GSL_EDOM, 0);

    }

  h = (gsl_histogram2d *) malloc (sizeof (gsl_histogram2d));

  if (h == 0)

    {

      GSL_ERROR_VAL ("failed to allocate space for histogram2d struct",

                        GSL_ENOMEM, 0);

    }

  h->xrange = (double *) malloc ((nx + 1) * sizeof (double));

  if (h->xrange == 0)

    {

      free (h);         /* exception in constructor, avoid memory leak */

      GSL_ERROR_VAL ("failed to allocate space for histogram2d x ranges",

                        GSL_ENOMEM, 0);

    }

  h->yrange = (double *) malloc ((ny + 1) * sizeof (double));

  if (h->yrange == 0)

    {

      free (h->xrange);

      free (h);         /* exception in constructor, avoid memory leak */

      GSL_ERROR_VAL ("failed to allocate space for histogram2d y ranges",

                        GSL_ENOMEM, 0);

    }

  h->bin = (double *) malloc (nx * ny * sizeof (double));

  if (h->bin == 0)

    {

      free (h->xrange);

      free (h->yrange);

      free (h);         /* exception in constructor, avoid memory leak */

      GSL_ERROR_VAL ("failed to allocate space for histogram bins",

                        GSL_ENOMEM, 0);

    }

  {

    size_t i;

    for (i = 0; i < nx + 1; i++)

      {

        h->xrange[i] = i;

      }

    for (i = 0; i < ny + 1; i++)

      {

        h->yrange[i] = i;

      }

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

      {

        h->bin[i] = 0;

      }

  }

  h->nx = nx;

  h->ny = ny;

  return h;

}

void

gsl_histogram2d_free (gsl_histogram2d * h)

{

  RETURN_IF_NULL (h);

  free (h->xrange);

  free (h->yrange);

  free (h->bin);

  free (h);

}

int 

gsl_histogram2d_set_ranges_uniform (gsl_histogram2d * h, 

                                    double xmin, double xmax,

                                    double ymin, double ymax)

{

  size_t i;

  const size_t nx = h->nx, ny = h->ny;

  if (xmin >= xmax)

    {

      GSL_ERROR_VAL ("xmin must be less than xmax", GSL_EINVAL, 0);

    }

  if (ymin >= ymax)

    {

      GSL_ERROR_VAL ("ymin must be less than ymax", GSL_EINVAL, 0);

    }

  /* initialize ranges */

  make_uniform (h->xrange, nx, xmin, xmax);

  make_uniform (h->yrange, ny, ymin, ymax);

  /* clear contents */

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

    {

      h->bin[i] = 0;

    }

  return GSL_SUCCESS;

}

int 

gsl_histogram2d_set_ranges (gsl_histogram2d * h, 

                            const double xrange[], size_t xsize,

                            const double yrange[], size_t ysize)

{

  size_t i;

  const size_t nx = h->nx, ny = h->ny;

  if (xsize != (nx + 1))

    {

      GSL_ERROR_VAL ("size of xrange must match size of histogram", 

                     GSL_EINVAL, 0);

    }

  if (ysize != (ny + 1))

    {

      GSL_ERROR_VAL ("size of yrange must match size of histogram", 

                     GSL_EINVAL, 0);

    }

  /* initialize ranges */

  for (i = 0; i <= nx; i++)

    {

      h->xrange[i] = xrange[i];

    }

  for (i = 0; i <= ny; i++)

    {

      h->yrange[i] = yrange[i];

    }

  /* clear contents */

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

    {

      h->bin[i] = 0;

    }

  return GSL_SUCCESS;

}