better document the "ghost_size gotcha"

git-svn-id: http://svn.cactuscode.org/arrangements/CactusBase/CoordBase/trunk@25 0337457d-221f-4ee6-a5f0-14255d5370d8

1 files changed, 12 insertions, 21 deletions

diff --git a/doc/documentation.tex b/doc/documentation.tex
index 42e576d..40abfd6 100644
--- a/doc/documentation.tex
+++ b/doc/documentation.tex
@@ -608,29 +608,20 @@ choose these parameters freely.
 When using the CoordBase domain and boundary parameters, the driver
 (PUGH, Carpet, etc) also needs to be kept informed.
 
+Whichever driver you're using, if you're specifying the number of boundary
+zones using CoordBase, note that this does \textbf{not} automatically
+carry over to the \verb|driver::ghost_size_x|, \verb|driver::ghost_size_y|,
+and \verb|driver::ghost_size_z| parameters.  If you want the ghost sizes
+to be anything other than their defaults (currently~$1$), you need to set
+them explicitly.
+
 \subsection{PUGH}
 
 If you're using PUGH, you \textbf{must} still explicitly set the
-parameters
-\begin{verbatim}
-driver::global_nx
-driver::global_ny
-driver::global_nz
-\end{verbatim}
-(Of course, you must set these to values consistent with the CoordBase
-parameters!)  (If you don't set these parameters, PUGH will assume a
-default $10 \times 10 \times 10$ grid, which is almost certainly not
-what you want!)
-
-You may also need to explicitly set the parameters
-\begin{verbatim}
-driver::ghost_size_x
-driver::ghost_size_y
-driver::ghost_size_z
-\end{verbatim}
-(again to values consistent with the CoordBase parameters!).  If you
-don't set these parameters, PUGH will assume a default of $1$ for
-each of them, which may not be what you want.
+parameters \verb|driver::global_nx|, \verb|driver::global_ny|,
+and \verb|driver::global_nz|.  If you don't set these parameters,
+PUGH will assume a default $10 \times 10 \times 10$~grid, which is
+almost certainly not what you want!
 
 \subsection{Carpet}
 
@@ -638,7 +629,7 @@ If you're using Carpet, things are nice:  just set
 \begin{verbatim}
 Carpet::domain_from_coordbase = true
 \end{verbatim}
-and Carpet will get all this information from CoordBase.
+and Carpet will get all its grid information from CoordBase.
 
 % Do not delete next line
 % END CACTUS THORNGUIDE