Fix swarm block neighbor indexing in 1D, 2D

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Current develop
 
 ### Added (new features/APIs/variables/...)
+- [[PR 1184]](https://github.com/parthenon-hpc-lab/parthenon/pull/1184) Fix swarm block neighbor indexing in 1D, 2D
 - [[PR 1183]](https://github.com/parthenon-hpc-lab/parthenon/pull/1183) Fix particle leapfrog example initialization data
 - [[PR 1179]](https://github.com/parthenon-hpc-lab/parthenon/pull/1179) Make a global variable for whether simulation is a restart
 - [[PR 1171]](https://github.com/parthenon-hpc-lab/parthenon/pull/1171) Add PARTHENON_USE_SYSTEM_PACKAGES build option

src/interface/swarm_comms.cpp

@@ -44,21 +44,6 @@ void Swarm::SetNeighborIndices_() {
     }
   }
 
-  // Indicate which neighbor regions correspond to this meshblock
-  const int kmin = ndim < 3 ? 0 : 1;
-  const int kmax = ndim < 3 ? 3 : 2;
-  const int jmin = ndim < 2 ? 0 : 1;
-  const int jmax = ndim < 2 ? 3 : 2;
-  const int imin = 1;
-  const int imax = 2;
-  for (int k = kmin; k <= kmax; k++) {
-    for (int j = jmin; j <= jmax; j++) {
-      for (int i = imin; i <= imax; i++) {
-        neighbor_indices_h(k, j, i) = this_block_;
-      }
-    }
-  }
-
   // Create a point in the center of each ghost halo region at maximum refinement level
   // and then test whether each neighbor block includes that point.
   const auto &bsize = pmb->block_size;
@@ -130,6 +115,21 @@ void Swarm::SetNeighborIndices_() {
     }
   }
 
+  // Indicate which neighbor regions correspond to this meshblock
+  const int kmin = ndim < 3 ? 0 : 1;
+  const int kmax = ndim < 3 ? 3 : 2;
+  const int jmin = ndim < 2 ? 0 : 1;
+  const int jmax = ndim < 2 ? 3 : 2;
+  const int imin = 1;
+  const int imax = 2;
+  for (int k = kmin; k <= kmax; k++) {
+    for (int j = jmin; j <= jmax; j++) {
+      for (int i = imin; i <= imax; i++) {
+        neighbor_indices_h(k, j, i) = this_block_;
+      }
+    }
+  }
+
   neighbor_indices_.DeepCopy(neighbor_indices_h);
 }
 

src/interface/swarm_device_context.hpp

@@ -75,9 +75,9 @@ class SwarmDeviceContext {
 
     // Ignore k,j indices as necessary based on problem dimension
     if (ndim_ == 1) {
-      block_index_(n) = neighbor_indices_(0, 0, i);
+      block_index_(n) = neighbor_indices_(1, 1, i);
     } else if (ndim_ == 2) {
-      block_index_(n) = neighbor_indices_(0, j, i);
+      block_index_(n) = neighbor_indices_(1, j, i);
     } else {
       block_index_(n) = neighbor_indices_(k, j, i);
     }