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[ctsim.git] / doc / ctsim-concepts.tex

diff --git a/doc/ctsim-concepts.tex b/doc/ctsim-concepts.tex
index 3f0bb1640554d5fe31f0415e017792f94566b778..bacfd4b4807969b66469c0833c9c682d08ee9c02 100644 (file)
--- a/doc/ctsim-concepts.tex
+++ b/doc/ctsim-concepts.tex
@@ -301,7 +301,7 @@ length}. This length,
 \latexonly{\begin{equation} d_l = 4\,f \tan (\alpha / 2)\end{equation}}
 \latexignore{\\\centerline{\emph{4 x F x tan(\alpha/2)}}}
 \latexonly{This geometry is shown in figure~\ref{equilinearfig}.}
-\begin{figure}\label{equilinearfig}
+\begin{figure}
 \centerline{\image{10cm;0cm}{equilinear.eps}}
 \latexonly{\caption{\label{equilinearfig} Equilinear geometry}}
 \end{figure}
@@ -316,7 +316,7 @@ accurate as filtered backprojection. This is due primarily
 to interpolation occurring in the frequency domain rather than the
 spatial domain.
 
-\subsection{Filtered Backprojection}\index{Filtered backprojection}
+\subsection{Filtered Backprojection}\index{Filtered backprojection}\index{Symmetric multiprocessing}\index{SMP}
 The technique is comprised of two sequential steps:
 filtering projections followed by backprojecting the filtered projections. Though
 these two steps are sequential, each view position can be processed independently.
@@ -324,9 +324,18 @@ these two steps are sequential, each view position can be processed independentl
 \subsubsection{Parallel Computer Processing}\index{Parallel processing}
 Since each view can be processed independently, filtered backprojection is amendable to
 parallel processing. Indeed, this has been used in commercial scanners to speed reconstruction.
-This parallelism is exploited in the MPI versions of \ctsim\ where the
-data from all the views are spread about amongst all of the
-processors. This has been testing in a cluster of 16 computers with excellent
+This parallelism is exploited both in the \ctsim\ graphical shell and
+in the \helpref{LAM}{ctsimtextlam} version of \ctsimtext. \ctsim\ can distribute it's workload
+amongst multiple processors working in parallel.
+
+The graphical shell will automatically take advantage of multiple CPU's when
+running on a \emph{Symmetric Multiprocessing}
+computer. Dual-CPU computers are commonly available which provide a near doubling
+in reconstruction speeds. \ctsim, though, has no limits on the number of CPU's
+that can be used in parallel. The \emph{LAM} version
+of \ctsimtext\ is designed to work in a cluster of computers.
+This has been testing with a cluster of 16 computers in a
+\urlref{Beowulf-class}{http://www.beowulf.org} cluster with excellent
 results.
 
 \subsubsection{Filter projections}