From 254940cbf37a6379e0335b1f7140e1ce8b45c6d1 Mon Sep 17 00:00:00 2001 From: bangerth Date: Sat, 16 Aug 2008 03:07:50 +0000 Subject: [PATCH] Add some reasoning to the documentation of a mesh smoothing flag. git-svn-id: https://svn.dealii.org/trunk@16573 0785d39b-7218-0410-832d-ea1e28bc413d --- deal.II/deal.II/include/grid/tria.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/deal.II/deal.II/include/grid/tria.h b/deal.II/deal.II/include/grid/tria.h index 45fcc6da0c..90c9960edd 100644 --- a/deal.II/deal.II/include/grid/tria.h +++ b/deal.II/deal.II/include/grid/tria.h @@ -816,6 +816,15 @@ namespace internal * after creation of the triangulation. It follows that active * cells on level 1 may not be coarsenend. * + * The main use of this flag is to ensure that each cell has at least one + * neighbor in each coordinate direction (i.e. each cell has at least a + * left or right, and at least an upper or lower neighbor in 2d). This is + * a necessary precondition for some algorihms that compute finite + * differences between cells. The DerivativeApproximation class is one of + * these algorithms that require that a triangulation is coarsest_level_1 + * unless all cells already have at least one neighbor in each coordinate + * direction on the coarsest level. + * *
  • @p smoothing_on_refinement: * This flag sums up all smoothing algorithms which may be performed upon * refinement by flagging some more cells for refinement. -- 2.39.5