GRHydro: Option to use the slow sector of multirate RK methods.

NOTE: This patch requires support from MoL.

Patch by Christian Reisswig.

git-svn-id: http://svn.einsteintoolkit.org/cactus/EinsteinEvolve/GRHydro/trunk@405 c83d129a-5a75-4d5a-9c4d-ed3a5855bf45

1 files changed, 19 insertions, 0 deletions

diff --git a/param.ccl b/param.ccl
index 75f26c2..a89d8cc 100644
--- a/param.ccl
+++ b/param.ccl
@@ -50,6 +50,7 @@ EXTENDS KEYWORD temperature_evolution_method ""
 shares: MethodOfLines
 
 USES CCTK_INT MoL_Num_Evolved_Vars
+USES CCTK_INT MoL_Num_Evolved_Vars_Slow
 USES CCTK_INT MoL_Num_Constrained_Vars
 USES CCTK_INT MoL_Num_SaveAndRestore_Vars
 USES CCTK_INT MoL_Max_Evolved_Array_Size 
@@ -76,9 +77,16 @@ CCTK_INT GRHydro_hydro_excision "Turns excision automatically on in HydroBase" A
 
 CCTK_INT GRHydro_MaxNumEvolvedVars "The maximum number of evolved variables used by GRHydro" ACCUMULATOR-BASE=MethodofLines::MoL_Num_Evolved_Vars
 {
+  0             :: "when using multirate"
   5:10		:: "dens scon[3] tau Bvec[3] psidc ye"
 } 5
 
+CCTK_INT GRHydro_MaxNumEvolvedVarsSlow "The maximum number of evolved variables used by GRHydro" ACCUMULATOR-BASE=MethodofLines::MoL_Num_Evolved_Vars_Slow
+{
+  0             :: "do not use multirate"
+  5:10		:: "dens scon[3] tau Bvec[3] psidc ye"
+} 0
+
 #  7  primitives (rho,press,eps,w_lorentz,vel)
 # 10  Tmunu
 #  3  Bvec
@@ -640,6 +648,17 @@ BOOLEAN sync_conserved_only "Only sync evolved conserved quantities during evolu
 } no
 
 
+restricted:
+# This uses the slow sector of MoL multirate methods.
+# Since the CFL requirements for hydro are less demanding,
+# it is possible to get a significant speed up by
+# using a lower order time integration such as RK2, while the spacetime
+# is still integrated with an RK4
+BOOLEAN use_MoL_slow_multirate_sector "Whether to make use of MoL's slow multirate sector"
+{
+} no
+private:
+
 
 
 BOOLEAN verbose "Some debug output"