CarpetRegrid2: Regrid only if the tracked objects have moved sufficiently

Regrid only if the tracked objects have moved a certain minimum
distance.

darcs-hash:20070311204027-dae7b-7c39e3c51d6b617188b477aed73facd5fe7e6fe8.gz

2 files changed, 41 insertions, 0 deletions

diff --git a/Carpet/CarpetRegrid2/src/initialise.cc b/Carpet/CarpetRegrid2/src/initialise.cc
index 3904a1d71..b2b7104db 100644
--- a/Carpet/CarpetRegrid2/src/initialise.cc
+++ b/Carpet/CarpetRegrid2/src/initialise.cc
@@ -134,6 +134,12 @@ namespace CarpetRegrid2 {
         radius[index2 (lsh, rl, 9)] = radius_10[rl];
       }
     }
+    
+    for (int n = 0; n < num_centres; ++ n) {
+      old_position_x[n] = position_x[n];
+      old_position_y[n] = position_y[n];
+      old_position_z[n] = position_z[n];
+    }
   }
   
 } // namespace CarpetRegrid2
diff --git a/Carpet/CarpetRegrid2/src/regrid.cc b/Carpet/CarpetRegrid2/src/regrid.cc
index 7ac61c7b4..9ee669564 100644
--- a/Carpet/CarpetRegrid2/src/regrid.cc
+++ b/Carpet/CarpetRegrid2/src/regrid.cc
@@ -561,6 +561,34 @@ namespace CarpetRegrid2 {
               Carpet::map > * last_map))));
       }
     }
+    
+    if (do_recompose and cctk_iteration != 0) {
+      // Regrid only if the positions have changed sufficiently
+      do_recompose = false;
+      for (int n = 0; n < num_centres; ++ n) {
+        CCTK_REAL const dist2 =
+          pow (position_x[n] - old_position_x[n], 2) +
+          pow (position_y[n] - old_position_y[n], 2) +
+          pow (position_z[n] - old_position_z[n], 2);
+        CCTK_REAL mindist;
+        switch (n) {
+        case 0: mindist = movement_threshold_1; break;
+        case 1: mindist = movement_threshold_2; break;
+        case 2: mindist = movement_threshold_3; break;
+        case 3: mindist = movement_threshold_4; break;
+        case 4: mindist = movement_threshold_5; break;
+        case 5: mindist = movement_threshold_6; break;
+        case 6: mindist = movement_threshold_7; break;
+        case 7: mindist = movement_threshold_8; break;
+        case 8: mindist = movement_threshold_9; break;
+        case 9: mindist = movement_threshold_10; break;
+        default: assert (0);
+        }
+        do_recompose = dist2 >= pow (mindist, 2);
+        if (do_recompose) break;
+      } // for n
+    }
+    
     if (do_recompose) {
       * last_iteration = cctk_iteration;
       * last_map = Carpet::map;
@@ -583,6 +611,13 @@ namespace CarpetRegrid2 {
       // Make multigrid aware
       Carpet::MakeMultigridBoxes (cctkGH, regss, regsss);
       
+      // Remember current positions
+      for (int n = 0; n < num_centres; ++ n) {
+        old_position_x[n] = position_x[n];
+        old_position_y[n] = position_y[n];
+        old_position_z[n] = position_z[n];
+      }
+      
     } // if do_recompose
     
     return do_recompose;