1 files changed, 87 insertions, 0 deletions
diff --git a/gsl-1.9/roots/convergence.c b/gsl-1.9/roots/convergence.c
new file mode 100644
index 0000000..34a78fe
--- /dev/null
+++ b/gsl-1.9/roots/convergence.c
@@ -0,0 +1,87 @@
+/* roots/convergence.c
+ * 
+ * Copyright (C) 1996, 1997, 1998, 1999, 2000 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 2 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_errno.h>
+#include <gsl/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 ;
+}
+