/* integration/err.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 <math.h>

#include <float.h>

#include <gsl/gsl_math.h>

#include <gsl/gsl_integration.h>

static double rescale_error (double err, const double result_abs, const double result_asc) ;

static double

rescale_error (double err, const double result_abs, const double result_asc)

{

  err = fabs(err) ;

  if (result_asc != 0 && err != 0)

      {

        double scale = pow((200 * err / result_asc), 1.5) ;

        if (scale < 1)

          {

            err = result_asc * scale ;

          }

        else 

          {

            err = result_asc ;

          }

      }

  if (result_abs > GSL_DBL_MIN / (50 * GSL_DBL_EPSILON))

    {

      double min_err = 50 * GSL_DBL_EPSILON * result_abs ;

      if (min_err > err) 

        {

          err = min_err ;

        }

    }

  return err ;

}