From 7aca8ff508386b43d4185ebd7429e43a81956c4a Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@math.tamu.edu>
Date: Thu, 10 Oct 2002 18:27:38 +0000
Subject: [PATCH] Fix DataOut::build_patches.

git-svn-id: https://svn.dealii.org/trunk@6626 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/doc/news/2002/c-3-4.html | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/deal.II/doc/news/2002/c-3-4.html b/deal.II/doc/news/2002/c-3-4.html
index 9faec1d2a7..563b071da1 100644
--- a/deal.II/doc/news/2002/c-3-4.html
+++ b/deal.II/doc/news/2002/c-3-4.html
@@ -364,6 +364,18 @@ contributor's names are abbreviated by WB (Wolfgang Bangerth), GK
 <h3>deal.II</h3>
 
 <ol>
+  <li> <p> 
+       Fixed: The algorithm to generate neighbor information for patches from
+       cells in <code class="member">DataOut::build_patches</code> was rather
+       inefficient, tripling the time for patch generation when support for
+       neighbor information was added. Furthermore, the algorithm was at least
+       O(N log N), where the rest was all O(N), making this particularly
+       problematic when the data set was already large. This should now be back
+       to the previous level, by using a more efficient algorithm.
+       <br>
+       (WB 2002/10/10)
+       </p>
+
   <li> <p> 
        Changed (internals): Previously, the finite element base class
        initialized the restriction, prolongation, and face constraints matrices
-- 
2.39.5