12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788 |
- /* roots/convergence.c
- *
- * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Reid Priedhorsky, 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 "gsl__config.h"
- #include "gsl_math.h"
- #include "gsl_errno.h"
- #include "gsl_roots.h"
- int
- gsl_root_test_interval (double x_lower, double x_upper, double epsabs, double epsrel)
- {
- const double abs_lower = fabs(x_lower) ;
- const double abs_upper = fabs(x_upper) ;
- double min_abs, tolerance;
- if (epsrel < 0.0)
- GSL_ERROR ("relative tolerance is negative", GSL_EBADTOL);
-
- if (epsabs < 0.0)
- GSL_ERROR ("absolute tolerance is negative", GSL_EBADTOL);
- if (x_lower > x_upper)
- GSL_ERROR ("lower bound larger than upper bound", GSL_EINVAL);
- if ((x_lower > 0.0 && x_upper > 0.0) || (x_lower < 0.0 && x_upper < 0.0))
- {
- min_abs = GSL_MIN_DBL(abs_lower, abs_upper) ;
- }
- else
- {
- min_abs = 0;
- }
- tolerance = epsabs + epsrel * min_abs ;
-
- if (fabs(x_upper - x_lower) < tolerance)
- return GSL_SUCCESS;
-
- return GSL_CONTINUE ;
- }
- int
- gsl_root_test_delta (double x1, double x0, double epsabs, double epsrel)
- {
- const double tolerance = epsabs + epsrel * fabs(x1) ;
- if (epsrel < 0.0)
- GSL_ERROR ("relative tolerance is negative", GSL_EBADTOL);
-
- if (epsabs < 0.0)
- GSL_ERROR ("absolute tolerance is negative", GSL_EBADTOL);
-
- if (fabs(x1 - x0) < tolerance || x1 == x0)
- return GSL_SUCCESS;
-
- return GSL_CONTINUE ;
- }
- int
- gsl_root_test_residual (double f, double epsabs)
- {
- if (epsabs < 0.0)
- GSL_ERROR ("absolute tolerance is negative", GSL_EBADTOL);
-
- if (fabs(f) < epsabs)
- return GSL_SUCCESS;
-
- return GSL_CONTINUE ;
- }
|