Added some more comments to document how the domain to reduce is set up.

git-svn-id: http://svn.cactuscode.org/arrangements/CactusPUGH/PUGHReduce/trunk@23 d60812e6-3970-4df4-986e-c251b06effeb

1 files changed, 6 insertions, 1 deletions

diff --git a/src/Reduction.c b/src/Reduction.c
index bce75e9..8ac7dfd 100644
--- a/src/Reduction.c
+++ b/src/Reduction.c
@@ -382,17 +382,20 @@ static int PUGH_ReductionGA (cGH *GH, int index, int proc, CCTK_REAL *outval,
   iterator       = from + 2*GA->connectivity->dim;
   points_per_dim = from + 3*GA->connectivity->dim;
 
-  /* get the start and endpoint to iterate over, the total number of points,
+  /* get the start- and endpoint to iterate over, the total number of points,
      and the points_per_dim[] vector */
   num_points = 1;
   points_per_dim[0] = 1;
   for (i = 0; i < GA->connectivity->dim; i++)
   {
+    /* find out whether the variable is staggered */
     stagger_index = CCTK_StaggerDirIndex (i, GA->stagger);
 
+    /* get the start- and endpoint to iterate over in this dimension */
     from[i] = GA->extras->ownership[stagger_index][0][i];
     to[i]   = GA->extras->ownership[stagger_index][1][i];
 
+    /* get the number of points in this dimension (excluding ghostzones) */
     dir_points = GA->extras->nsize[i];
     if (GA->connectivity->perme[i])
     {
@@ -402,6 +405,8 @@ static int PUGH_ReductionGA (cGH *GH, int index, int proc, CCTK_REAL *outval,
     {
       dir_points--;
     }
+
+    /* accumulate the total number of points the reduce */
     num_points *= dir_points;
 
     if (i > 0)