From 72bc74698d076c33e7c07355b6103612af22da74 Mon Sep 17 00:00:00 2001 From: Wolfgang Bangerth Date: Sun, 31 Dec 2017 15:25:20 -0700 Subject: [PATCH] Update a couple of comments. --- include/deal.II/distributed/shared_tria.h | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/include/deal.II/distributed/shared_tria.h b/include/deal.II/distributed/shared_tria.h index defd14a5a9..fae5637e10 100644 --- a/include/deal.II/distributed/shared_tria.h +++ b/include/deal.II/distributed/shared_tria.h @@ -120,10 +120,13 @@ namespace parallel enum Settings { /** - * Choose the partitioner depending on the enabled dependencies. - * If Zoltan is available, partition_zoltan is used. If METIS is - * supported partition_metis is chosen afterwards, else - * partition_zorder is taken as partitioning strategy. + * Choose the partitioner depending on the enabled + * dependencies that were found when configuring deal.II. In + * particular, if the Trilinos package Zoltan was found, then + * use the @p partition_zoltan strategy. If Zoltan was not + * found but the METIS package was found, then use the + * partition_metis strategy. If neither of these were found, + * then use the partition_zorder partitioning strategy. */ partition_auto = 0x0, @@ -135,6 +138,16 @@ namespace parallel /** * Partition active cells with the same scheme used in the * p4est library. + * + * The term "Z-order" originates in the fact that cells are + * sorted using a space filling curve which in 2d connects the + * four children of a cell in the order bottom left, bottom + * right, top left, top right (i.e., with a curve that looks + * like a reverse "Z"), and does so recursively on all levels + * of a triangulation. This is also the order in which + * children are enumerated by the GeometryInfo class. The + * "Z-order" is also sometimes called "Morton ordering", see + * https://en.wikipedia.org/wiki/Z-order_curve . */ partition_zorder = 0x2, -- 2.39.5