From: Wolfgang Bangerth Date: Fri, 8 Jul 2016 00:32:00 +0000 (-0500) Subject: Add some documentation. X-Git-Tag: v8.5.0-rc1~901^2 X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=071ad5fc7b712f67a5fdbe79a431a68d515352a9;p=dealii.git Add some documentation. --- diff --git a/include/deal.II/grid/grid_generator.h b/include/deal.II/grid/grid_generator.h index cace929cda..0df104b0bf 100644 --- a/include/deal.II/grid/grid_generator.h +++ b/include/deal.II/grid/grid_generator.h @@ -128,14 +128,25 @@ namespace GridGenerator * Create a coordinate-parallel brick from the two diagonally opposite * corner points @p p1 and @p p2. * - * If the @p colorize flag is set, the @p boundary_ids of the surfaces are + * If the @p colorize flag is @p true, the @p boundary_ids of the boundary faces are * assigned, such that the lower one in @p x-direction is 0, the upper one * is 1. The indicators for the surfaces in @p y-direction are 2 and 3, the - * ones for @p z are 4 and 5. Additionally, material ids are assigned to the + * ones for @p z are 4 and 5. This corresponds to the numbers of faces + * of the unit square of cube as laid out in the documentation of the + * GeometryInfo class. Importantly, however, in 3d colorization does not + * set @p boundary_ids of edges, but only of faces, because + * each boundary edge is shared between two faces and it is not clear how + * the boundary id of an edge should be set in that case. This may later on + * lead to problems if one wants to assign boundary or manifold objects to + * parts of the boundary with certain boundary indicators since then the + * boundary object may not apply to the edges bounding the face it is meant + * to describe. + * + * Additionally, if @p colorize is @p true, material ids are assigned to the * cells according to the octant their center is in: being in the right half - * plane for any coordinate direction xi adds - * 2i. For instance, the center point (1,-1,1) yields a material - * id 5. + * space for any coordinate direction xi adds + * 2i. For instance, a cell with center point (1,-1,1) yields a material + * id 5, assuming that the center of the hyper rectangle lies at the origin. * * If @p dim < @p spacedim, this will create a @p dim dimensional object in * the first @p dim coordinate directions embedded into the @p spacedim @@ -196,7 +207,8 @@ namespace GridGenerator * * @param p2 Second corner opposite to @p p1. * - * @param colorize Assign different boundary ids if set to true. + * @param colorize Assign different boundary ids if set to true. The + * same comments apply as for the hyper_rectangle() function. * */ template