/* multiroots/fsolver.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 <string.h>

#include <gsl/gsl_errno.h>

#include <gsl/gsl_multiroots.h>

gsl_multiroot_fsolver * 

gsl_multiroot_fsolver_alloc (const gsl_multiroot_fsolver_type * T,

                                     size_t n)

{

  int status;

  gsl_multiroot_fsolver * s;

  s = (gsl_multiroot_fsolver *) malloc (sizeof (gsl_multiroot_fsolver));

  if (s == 0)

    {

      GSL_ERROR_VAL ("failed to allocate space for multiroot solver struct",

                        GSL_ENOMEM, 0);

    }

  s->x = gsl_vector_calloc (n);

  if (s->x == 0) 

    {

      free (s);

      GSL_ERROR_VAL ("failed to allocate space for x", GSL_ENOMEM, 0);

    }

  s->f = gsl_vector_calloc (n);

  if (s->f == 0) 

    {

      gsl_vector_free (s->x);

      free (s);

      GSL_ERROR_VAL ("failed to allocate space for f", GSL_ENOMEM, 0);

    }

  s->dx = gsl_vector_calloc (n);

  if (s->dx == 0) 

    {

      gsl_vector_free (s->x);

      gsl_vector_free (s->f);

      free (s);

      GSL_ERROR_VAL ("failed to allocate space for dx", GSL_ENOMEM, 0);

    }

  s->state = malloc (T->size);

  if (s->state == 0)

    {

      gsl_vector_free (s->dx);

      gsl_vector_free (s->x);

      gsl_vector_free (s->f);

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

      GSL_ERROR_VAL ("failed to allocate space for multiroot solver state",

                        GSL_ENOMEM, 0);

    }

  s->type = T ;

  status = (s->type->alloc)(s->state, n);

  if (status != GSL_SUCCESS)

    {

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

      free (s->state);

      gsl_vector_free (s->dx);

      gsl_vector_free (s->x);

      gsl_vector_free (s->f);

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

      GSL_ERROR_VAL ("failed to set solver", status, 0);

    }

  s->function = NULL;

  return s;

}

int

gsl_multiroot_fsolver_set (gsl_multiroot_fsolver * s, 

                           gsl_multiroot_function * f, 

                           const gsl_vector * x)

{

  if (s->x->size != f->n)

    {

      GSL_ERROR ("function incompatible with solver size", GSL_EBADLEN);

    }

  if (x->size != f->n)

    {

      GSL_ERROR ("vector length not compatible with function", GSL_EBADLEN);

    }  

  s->function = f;

  gsl_vector_memcpy(s->x,x);

  return (s->type->set) (s->state, s->function, s->x, s->f, s->dx);

}

int

gsl_multiroot_fsolver_iterate (gsl_multiroot_fsolver * s)

{

  return (s->type->iterate) (s->state, s->function, s->x, s->f, s->dx);

}

void

gsl_multiroot_fsolver_free (gsl_multiroot_fsolver * s)

{

  RETURN_IF_NULL (s);

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

  free (s->state);

  gsl_vector_free (s->dx);

  gsl_vector_free (s->x);

  gsl_vector_free (s->f);

  free (s);

}

const char *

gsl_multiroot_fsolver_name (const gsl_multiroot_fsolver * s)

{

  return s->type->name;

}

gsl_vector *

gsl_multiroot_fsolver_root (const gsl_multiroot_fsolver * s)

{

  return s->x;

}

gsl_vector *

gsl_multiroot_fsolver_dx (const gsl_multiroot_fsolver * s)

{

  return s->dx;

}

gsl_vector *

gsl_multiroot_fsolver_f (const gsl_multiroot_fsolver * s)

{

  return s->f;

}