From b01b913ca076c440ab27712335b57292e9711a58 Mon Sep 17 00:00:00 2001 From: bangerth Date: Thu, 11 Dec 2008 23:06:02 +0000 Subject: [PATCH] Document FEValuesViews changes. git-svn-id: https://svn.dealii.org/trunk@17921 0785d39b-7218-0410-832d-ea1e28bc413d --- deal.II/doc/news/changes.h | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/deal.II/doc/news/changes.h b/deal.II/doc/news/changes.h index 4c412e0214..ed988f0d1b 100644 --- a/deal.II/doc/news/changes.h +++ b/deal.II/doc/news/changes.h @@ -600,7 +600,24 @@ inconvenience this causes.
  1. - Upgraded: The FunctionParser classes now use version 2.83. + Improved: The FEValuesViews objects that one gets when writing things + like fe_values[velocities] (see @ref vector_valued) have + become a lot smarter. They now compute a significant amount of data + at creation time, rather than on the fly. This means that creating such + objects becomes more expensive but using them is cheaper. To offset this + cost, FEValuesBase objects now create all possible FEValuesViews objects + at creation time, rather than whenever you do things like + fe_values[velocities], and simply return a reference to a + pre-generated object. This turns an $O(N)$ effort into an $O(1)$ + effort, where $N$ is the number of cells. +
    + (Luca Heltai 2008/12/08) +

    + +
  2. +

    + Upgraded: The FunctionParser classes now use version 2.83 of the fparser + library.
    (Luca Heltai 2008/12/08)

    -- 2.39.5