From d7d719472b1b5047efdaa22cfab0a47b34e754e3 Mon Sep 17 00:00:00 2001 From: bangerth Date: Mon, 15 Aug 2011 00:37:38 +0000 Subject: [PATCH] Add a link and other minor additions. git-svn-id: https://svn.dealii.org/trunk@24064 0785d39b-7218-0410-832d-ea1e28bc413d --- deal.II/examples/step-2/doc/results.dox | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/deal.II/examples/step-2/doc/results.dox b/deal.II/examples/step-2/doc/results.dox index c9a6e0f44c..6f209e32c0 100644 --- a/deal.II/examples/step-2/doc/results.dox +++ b/deal.II/examples/step-2/doc/results.dox @@ -1,7 +1,10 @@

Results

The program has, after having been run, produced two sparsity -patterns. We can visualize them using GNUPLOT: +patterns. We can visualize them using GNUPLOT (one of the simpler visualization +programs; maybe not the easiest to use since it is command line driven, but +also universally available on all linux and other unix-like systems): @code examples/step-2> gnuplot @@ -26,12 +29,12 @@ gnuplot> set style data points gnuplot> plot "sparsity_pattern.1" @endcode -The results then look like this (every cross denotes an entry which +The results then look like this (every point denotes an entry which might be nonzero; of course the fact whether the entry actually is zero or not depends on the equation under consideration, but the indicated positions in the matrix tell us which shape functions can -and which can't couple, if the equation is a local, i.e. differential -one): +and which can't couple when discretizing a local, i.e. differential, +equation):
@@ -44,7 +47,8 @@ one):
-The different regions in the left picture represent the degrees of +The different regions in the left picture, indicated by kinks in the lines and +single dots on the left and top, represent the degrees of freedom on the different refinement levels of the triangulation. As can be seen in the right picture, the sparsity pattern is much better clustered around the main diagonal of the matrix after @@ -70,4 +74,5 @@ diagonal), though the ratio of bandwidth to size typically shrinks, i.e. the matrix clusters more around the diagonal. Another idea of experiments would be to try other renumbering -strategies than Cuthill-McKee from the DoFRenumbering namespace. +strategies than Cuthill-McKee from the DoFRenumbering namespace and see how +they affect the sparsity pattern. -- 2.39.5