/* vector/subvector_source.c

 * 

 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Gerard Jungman, 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.

 */

QUALIFIED_VIEW(_gsl_vector, view)

FUNCTION(gsl_vector, subvector) (QUALIFIED_TYPE(gsl_vector) * v, size_t offset, size_t n)

{

  QUALIFIED_VIEW(_gsl_vector,view) view = NULL_VECTOR_VIEW;

  if (offset + (n > 0 ? n - 1 : 0) >= v->size)

    {

      GSL_ERROR_VAL ("view would extend past end of vector", 

                     GSL_EINVAL, view);

    }

  {

    TYPE(gsl_vector) s = NULL_VECTOR;

    s.data = v->data +  MULTIPLICITY * v->stride * offset ;

    s.size = n;

    s.stride = v->stride;

    s.block = v->block;

    s.owner = 0;

    view.vector = s;

    return view;

  }

}

QUALIFIED_VIEW(_gsl_vector, view)

FUNCTION(gsl_vector, subvector_with_stride) (QUALIFIED_TYPE(gsl_vector) * v, size_t offset, size_t stride, size_t n)

{

  QUALIFIED_VIEW(_gsl_vector,view) view = NULL_VECTOR_VIEW;

  if (stride == 0)

    {

      GSL_ERROR_VAL ("stride must be positive integer", 

                     GSL_EINVAL, view);

    }

  if (offset + (n > 0 ? n - 1 : 0) * stride >= v->size)

    {

      GSL_ERROR_VAL ("view would extend past end of vector", 

                     GSL_EINVAL, view);

    }

  {

    TYPE(gsl_vector) s = NULL_VECTOR;

    s.data = v->data + MULTIPLICITY * v->stride * offset ;

    s.size = n;

    s.stride = v->stride * stride;

    s.block = v->block;

    s.owner = 0;

    view.vector = s;

    return view;

  }

}