/* itersolve.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 <gsl/gsl_math.h>

#include <gsl/gsl_vector.h>

#include <gsl/gsl_matrix.h>

#include <gsl/gsl_errno.h>

#include <gsl/gsl_spmatrix.h>

#include <gsl/gsl_spblas.h>

#include <gsl/gsl_splinalg.h>

gsl_splinalg_itersolve *

gsl_splinalg_itersolve_alloc(const gsl_splinalg_itersolve_type *T,

                             const size_t n, const size_t m)

{

  gsl_splinalg_itersolve *w;

  w = calloc(1, sizeof(gsl_splinalg_itersolve));

  if (w == NULL)

    {

      GSL_ERROR_NULL("failed to allocate space for itersolve struct",

                     GSL_ENOMEM);

    }

  w->type = T;

  w->normr = 0.0;

  w->state = w->type->alloc(n, m);

  if (w->state == NULL)

    {

      gsl_splinalg_itersolve_free(w);

      GSL_ERROR_NULL("failed to allocate space for itersolve state",

                     GSL_ENOMEM);

    }

  return w;

} /* gsl_splinalg_itersolve_alloc() */

void

gsl_splinalg_itersolve_free(gsl_splinalg_itersolve *w)

{

  RETURN_IF_NULL(w);

  if (w->state)

    w->type->free(w->state);

  free(w);

}

const char *

gsl_splinalg_itersolve_name(const gsl_splinalg_itersolve *w)

{

  return w->type->name;

}

int

gsl_splinalg_itersolve_iterate(const gsl_spmatrix *A, const gsl_vector *b,

                               const double tol, gsl_vector *x,

                               gsl_splinalg_itersolve *w)

{

  int status = w->type->iterate(A, b, tol, x, w->state);

  /* store current residual */

  w->normr = w->type->normr(w->state);

  return status;

}

double

gsl_splinalg_itersolve_normr(const gsl_splinalg_itersolve *w)

{

  return w->normr;

}