Adaptive step size control using RK45. Due to Erik Schnetter.

Note that if you want to use this with Carpet you currently have to
use the development (darcs) version of Carpet together with the
parameter

carpet::adaptive_stepsize = "yes".


git-svn-id: http://svn.cactuscode.org/arrangements/CactusNumerical/MoL/trunk@82 578cdeb0-5ea1-4b81-8215-5a3b8777ee0b

1 files changed, 38 insertions, 0 deletions

diff --git a/param.ccl b/param.ccl
index a65216a..d9b6265 100644
--- a/param.ccl
+++ b/param.ccl
@@ -132,6 +132,44 @@ BOOLEAN disable_prolongation "If Mesh refinement is enabled should we use buffer
 {
 } "yes"
 
+
+
+BOOLEAN adaptive_stepsize "Choose the time step size adaptively"
+{
+} "no"
+
+REAL maximum_absolute_error "Maximum allowed absolute error for adaptive stepsize control"
+{
+  (0.0:*) :: ""
+} 1.0e-6
+
+REAL maximum_relative_error "Maximum allowed relative error for adaptive stepsize control"
+{
+  (0.0:*) :: ""
+} 1.0e-6
+
+REAL RHS_error_weight "Weight of the RHS in the relative error calculation"
+{
+  0.0:* :: "should be between zero and one"
+} 1.0
+
+REAL safety_factor "Safety factor for stepsize control"
+{
+  (0.0:*) :: "should be less than one"
+} 0.9
+
+REAL maximum_decrease "Maximum stepsize decrease factor"
+{
+  (0.0:*) :: "should be larger than one"
+} 10.0
+
+REAL maximum_increase "Maximum stepsize increase factor"
+{
+  (0.0:*) :: "should be larger than one"
+} 5.0
+
+
+
 KEYWORD verbose "How verbose should MoL be?"
 {
   "none"     :: "No output at all (not implemented)"