PunctureTracker: Abort with sensible error message on NaNs or excessively large values of interpolated beta

git-svn-id: http://svn.aei.mpg.de/numrel/AEIThorns/PunctureTracker/trunk@17 a2659f00-0f4f-0410-9214-a4596bbb8a4f

2 files changed, 24 insertions, 0 deletions

diff --git a/param.ccl b/param.ccl
index 89ac90e..fd1fe5f 100644
--- a/param.ccl
+++ b/param.ccl
@@ -45,6 +45,10 @@ INT which_surface_to_store_info[10] "A spherical surface index where we can stor
   0:* :: "any spherical surface index"
 } -1
 
+REAL shift_limit "Shift components must be less than this in magnitude"
+{
+  0.0:* :: "zero or positive"
+} 1.0e10
 
 PRIVATE:
 
diff --git a/src/puncture_tracker.c b/src/puncture_tracker.c
index 8c3341b..f973d49 100644
--- a/src/puncture_tracker.c
+++ b/src/puncture_tracker.c
@@ -202,6 +202,26 @@ PunctureTracker_Track (CCTK_ARGUMENTS)
           }
         }
       }
+
+      // Check for NaNs and large shift components
+      if (CCTK_MyProc(cctkGH) == 0) {
+        for (int n = 0; n < max_num_tracked; ++ n) {
+          if (track[n]) {
+            CCTK_REAL norm = sqrt(pow((double) pt_betax[n],2) + 
+                                  pow((double) pt_betay[n],2) + 
+                                  pow((double) pt_betaz[n],2));
+
+            if (!isfinite(norm) || norm > shift_limit) {
+              CCTK_VWarn(0, __LINE__, __FILE__, CCTK_THORNSTRING,
+                         "Shift at puncture #%d is (%g,%g,%g).  This likely indicates an error in the simulation.",
+                         n,
+                         (double) pt_betax[n],
+                         (double) pt_betay[n],
+                         (double) pt_betaz[n]);
+            }
+          }
+        }
+      }
       
       // Time evolution