/* spprop.c

 * 

 * Copyright (C) 2014 Patrick Alken

 * 

 * 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 <gsl/gsl_spmatrix.h>

#include <gsl/gsl_errno.h>

/*

gsl_spmatrix_equal()

  Return 1 if a = b, 0 otherwise

*/

int

gsl_spmatrix_equal(const gsl_spmatrix *a, const gsl_spmatrix *b)

{

  const size_t M = a->size1;

  const size_t N = a->size2;

  if (b->size1 != M || b->size2 != N)

    {

      GSL_ERROR_VAL("matrices must have same dimensions", GSL_EBADLEN, 0);

    }

  else if (a->sptype != b->sptype)

    {

      GSL_ERROR_VAL("trying to compare different sparse matrix types", GSL_EINVAL, 0);

    }

  else

    {

      const size_t nz = a->nz;

      size_t n;

      if (nz != b->nz)

        return 0; /* different number of non-zero elements */

      if (GSL_SPMATRIX_ISTRIPLET(a))

        {

          /*

           * triplet formats could be out of order but identical, so use

           * gsl_spmatrix_get() on b for each aij

           */

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

            {

              double bij = gsl_spmatrix_get(b, a->i[n], a->p[n]);

              if (a->data[n] != bij)

                return 0;

            }

        }

      else if (GSL_SPMATRIX_ISCCS(a))

        {

          /*

           * for CCS, both matrices should have everything

           * in the same order

           */

          /* check row indices and data */

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

            {

              if ((a->i[n] != b->i[n]) || (a->data[n] != b->data[n]))

                return 0;

            }

          /* check column pointers */

          for (n = 0; n < a->size2 + 1; ++n)

            {

              if (a->p[n] != b->p[n])

                return 0;

            }

        }

      else if (GSL_SPMATRIX_ISCRS(a))

        {

          /*

           * for CRS, both matrices should have everything

           * in the same order

           */

          /* check column indices and data */

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

            {

              if ((a->i[n] != b->i[n]) || (a->data[n] != b->data[n]))

                return 0;

            }

          /* check row pointers */

          for (n = 0; n < a->size1 + 1; ++n)

            {

              if (a->p[n] != b->p[n])

                return 0;

            }

        }

      else

        {

          GSL_ERROR_VAL("unknown sparse matrix type", GSL_EINVAL, 0);

        }

      return 1;

    }

} /* gsl_spmatrix_equal() */