Allow negative timesteps

git-svn-id: http://svn.cactuscode.org/arrangements/CactusBase/Time/trunk@39 5633253d-7678-4964-a54d-f87795f8ee59

1 files changed, 6 insertions, 4 deletions

diff --git a/param.ccl b/param.ccl
index 30fa3ff..3776b46 100644
--- a/param.ccl
+++ b/param.ccl
@@ -5,10 +5,10 @@ restricted:
 
 KEYWORD timestep_method "Method for calculating timestep"
 {
- "given"     :: "Use given timestep"
+ "given"          :: "Use given timestep"
  "courant_static" :: "Courant condition at BASEGRID"
  "courant_speed"  :: "Courant condition at PRESTEP (using wavespeed)"
- "courant_time" :: "Courant condition at PRESTEP (using min time)"
+ "courant_time"   :: "Courant condition at PRESTEP (using min time)"
 } "courant_static"
 
 BOOLEAN timestep_outonly "Don't set a dynamic timestep, just output what it would be"
@@ -24,12 +24,14 @@ REAL timestep "Absolute value for timestep"
 
 REAL dtfac "The standard timestep condition dt = dtfac*max(delta_space)"
 {
- 0:* :: "Probably only makes sense to be bigger than zero"
+ 0:* :: "For positive timestep"
+ *:0 :: "For negative timestep"
 } 0.5 
 
 REAL courant_fac "The courant timestep condition dt = courant_fac*max(delta_space)/speed/sqrt(dim)"
 {
- 0:* :: "Probably only makes sense to be bigger than zero"
+ 0:* :: "For positive timestep"
+ *:0 :: "For negative timestep"
 } 0.9
 
 INT outtimestep_every "How often to output courant timestep"