document

   max_allowable_horizon_radius
option


git-svn-id: http://svn.einsteintoolkit.org/cactus/EinsteinAnalysis/AHFinderDirect/trunk@1206 f88db872-0e4f-0410-b76b-b9085cfa78c5

1 files changed, 20 insertions, 3 deletions

diff --git a/doc/documentation.tex b/doc/documentation.tex
index 4b49aae..46a8ec8 100644
--- a/doc/documentation.tex
+++ b/doc/documentation.tex
@@ -168,7 +168,7 @@ derivation of equation~\eqref{AHFinderDirect/eqn-horizon}.)
 of~\eqref{AHFinderDirect/eqn-horizon} by any specified nonzero
 constant, \ie{} you can find a surface of constant
 (in general nonzero) expansion.; this is dicsussed in
-section~\ref{AHFinderDirect/sect-parameters/other-IO-parameters}.)
+section~\ref{AHFinderDirect/sect-parameters/other-parameters}.)
 
 Thorn~\thorn{AHFinderDirect} finds an apparent horizon by numerically
 solving equation~\eqref{AHFinderDirect/eqn-horizon}.  It requires
@@ -1117,7 +1117,7 @@ each time that apparent horizon is found:
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 \subsection{Other Parameters}
-\label{AHFinderDirect/sect-parameters/other-IO-parameters}
+\label{AHFinderDirect/sect-parameters/other-parameters}
 
 \begin{description}
 \item[%%%
@@ -1184,6 +1184,23 @@ each time that apparent horizon is found:
 	get better resolution; 30~should be enough for even a
 	highly non-spherical horizon.
 
+\item[\code{max\_allowable\_horizon\_radius[}$n$\code{]}]
+\mbox{}\\
+	This parameter gives the maximum mean-coordinate-radius
+	which any given apparent horizon may have.%%%
+\footnote{%%%
+	 Note that this is an unweighted arithmetic
+	 mean over the horizon-surface grid points,
+	 the same value which is printed as \code{r\_grid}
+	 during the horizon-finding iterations.
+	 }%%%
+{}	This defaults to $10^{10}$ (effectively $+\infty$) for
+	each apparent horizon.  You can set it to a smaller value
+	to make \thorn{AHFinderDirect} a bit more efficient, or
+	(probably more important in practice) to stop
+	\thorn{AHFinderDirect} from iterating off the edge of the grid
+	if this causes problems with interpolation or boundary conditions.
+
 \item[\code{surface\_expansion[}$n$\code{]}]
 \mbox{}\\
 	This parameter (which defaults to 0.0) sets the expansion
@@ -1228,7 +1245,7 @@ is doing during a Cactus run: the \verb|BH_diagnostics| files and the
 \verb|CCTK_INFO| messages written to the Cactus standard output:
 
 The \verb|BH_diagnostics| files are described in detail in
-section~\ref{AHFinderDirect/sect-parameters/other-IO-parameters}.
+section~\ref{AHFinderDirect/sect-parameters/other-parameters}.
 These files are written and ``flushed'' at each time step, so they're
 always up-to-date.