add a bunch of comments

git-svn-id: http://svn.einsteintoolkit.org/cactus/EinsteinAnalysis/AHFinderDirect/trunk@484 f88db872-0e4f-0410-b76b-b9085cfa78c5

2 files changed, 24 insertions, 2 deletions

diff --git a/src/patch/ghost_zone.hh b/src/patch/ghost_zone.hh
index 115822b..53c4bd4 100644
--- a/src/patch/ghost_zone.hh
+++ b/src/patch/ghost_zone.hh
@@ -197,8 +197,7 @@
 //	it would be better to take the average of the two neighbors,
 //	but in practice this doesn't matter for horizon finding
 //	or other elliptic stuff (it would matter for stability in
-//	time evolutions using patch-angular finite differencing,
-//	eg in my "mpe" multipatch black-hole-excision code).]
+//	time evolutions using multipatch finite differencing).]
 //
 
 //*****************************************************************************
diff --git a/src/patch/patch_interp.hh b/src/patch/patch_interp.hh
index 85045eb..0708b9f 100644
--- a/src/patch/patch_interp.hh
+++ b/src/patch/patch_interp.hh
@@ -56,6 +56,29 @@
 // iperp, so it's ok to use (iperp,parindex) as a 2-D rectangular
 // index space.
 //
+// For example, we might interpolate at the points
+//            ipar ipar ipar ipar ipar ipar ipar ipar ipar
+//              1    2    3    4    5    6    7    8    9    
+// iperp=10           (2a)   (3b)   (4c)
+// iperp=11          (2d)   (3e)  (4f)   (5g)
+// where the (2a) etc are the interpolation points, with 2 etc being
+// the parindex values and a etc being unique identifiers used in our
+// description below.  In terms of our member data, this interpolation
+// region would be described by
+//	[min,max]_iperp_=[10,11]
+//	[min,max]_ipar_=[1,9]
+//	[min,max]_parindex_used_(10)=[2,5]
+//	[min,max]_parindex_used_(11)=[2,6]
+//	interp_par_(10,2) = x[a]
+//	interp_par_(10,3) = x[b]
+//	interp_par_(10,4) = x[c]
+//	interp_par_(11,2) = x[d]
+//	interp_par_(11,3) = x[e]
+//	interp_par_(11,4) = x[f]
+//	interp_par_(11,5) = x[g]
+//
+
+//
 // We use the Cactus local interpolator CCTK_InterpLocalUniform()
 // to do the interpolation.  To minimize interpolator overheads, we
 // interpolate all the gridfns at each iperp in a single interpolator