/* histogram/ntuple.c

 * 

 * Copyright (C) 2000 Simone Piccardi

 * 

 * 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.

 */

/* Jan/2001 Modified by Brian Gough. Minor changes for GSL */

#include <config.h>

#include <errno.h>

#include <gsl/gsl_errno.h>

#include <gsl/gsl_ntuple.h>

/* 

 * gsl_ntuple_open:

 * Initialize an ntuple structure and create the related file

 */

gsl_ntuple *

gsl_ntuple_create (char *filename, void *ntuple_data, size_t size)

{

  gsl_ntuple *ntuple = (gsl_ntuple *)malloc (sizeof (gsl_ntuple));

  if (ntuple == 0)

    {

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

                     GSL_ENOMEM, 0);

    }

  ntuple->ntuple_data = ntuple_data;

  ntuple->size = size;

  ntuple->file = fopen (filename, "wb");

  if (ntuple->file == 0)

    {

      free (ntuple);

      GSL_ERROR_VAL ("unable to create ntuple file", GSL_EFAILED, 0);

    }

  return ntuple;

}

/* 

 * gsl_ntuple_open:

 * Initialize an ntuple structure and open the related file

 */

gsl_ntuple *

gsl_ntuple_open (char *filename, void *ntuple_data, size_t size)

{

  gsl_ntuple *ntuple = (gsl_ntuple *)malloc (sizeof (gsl_ntuple));

  if (ntuple == 0)

    {

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

                     GSL_ENOMEM, 0);

    }

  ntuple->ntuple_data = ntuple_data;

  ntuple->size = size;

  ntuple->file = fopen (filename, "rb");

  if (ntuple->file == 0)

    {

      free (ntuple);

      GSL_ERROR_VAL ("unable to open ntuple file for reading", 

                     GSL_EFAILED, 0);

    }

  return ntuple;

}

/* 

 * gsl_ntuple_write:

 * write to file a data row, must be used in a loop!

 */

int

gsl_ntuple_write (gsl_ntuple * ntuple)

{

  size_t nwrite;

  nwrite = fwrite (ntuple->ntuple_data, ntuple->size,

                   1, ntuple->file);

  if (nwrite != 1)

    {

      GSL_ERROR ("failed to write ntuple entry to file", GSL_EFAILED);

    }

  return GSL_SUCCESS;

}

/* the following function is a synonym for gsl_ntuple_write */

int

gsl_ntuple_bookdata (gsl_ntuple * ntuple)

{

  return gsl_ntuple_write (ntuple);

}

/* 

 * gsl_ntuple_read:

 * read form file a data row, must be used in a loop!

 */

int

gsl_ntuple_read (gsl_ntuple * ntuple)

{

  size_t nread;

  nread = fread (ntuple->ntuple_data, ntuple->size, 1, ntuple->file);

  if (nread == 0 && feof(ntuple->file))

    {

      return GSL_EOF;

    }

  if (nread != 1)

    {

      GSL_ERROR ("failed to read ntuple entry from file", GSL_EFAILED);

    }

  return GSL_SUCCESS;

}

/* 

 * gsl_ntuple_project:

 * fill an histogram with an ntuple file contents, use

 * SelVal and SelFunc user defined functions to get 

 * the value to book and the selection funtion

 */

#define EVAL(f,x) ((*((f)->function))(x,(f)->params))

int

gsl_ntuple_project (gsl_histogram * h, gsl_ntuple * ntuple,

                    gsl_ntuple_value_fn * value_func, 

                    gsl_ntuple_select_fn * select_func)

{

  size_t nread;

  do

    {

      nread = fread (ntuple->ntuple_data, ntuple->size,

                     1, ntuple->file);

      if (nread == 0 && feof(ntuple->file))

        {

          break ;

        }

      if (nread != 1) 

        {

          GSL_ERROR ("failed to read ntuple for projection", GSL_EFAILED);

        }

      if (EVAL(select_func, ntuple->ntuple_data))

        {

          gsl_histogram_increment (h, EVAL(value_func, ntuple->ntuple_data));

        }

    }

  while (1);

  return GSL_SUCCESS;

}

/* 

 * gsl_ntuple_close:

 * close the ntuple file and free the memory

 */

int

gsl_ntuple_close (gsl_ntuple * ntuple)

{

  int status = fclose (ntuple->file);

  if (status)

    {

      GSL_ERROR ("failed to close ntuple file", GSL_EFAILED);

    }

  free (ntuple);

  return GSL_SUCCESS;

}