From be0799d91edcdb0ea56e4ae1e6436619af1c8272 Mon Sep 17 00:00:00 2001 From: heister Date: Sun, 17 Feb 2013 18:07:40 +0000 Subject: [PATCH] update step-49 git-svn-id: https://svn.dealii.org/trunk@28442 0785d39b-7218-0410-832d-ea1e28bc413d --- deal.II/examples/step-49/doc/intro.dox | 55 ++++++++++++++++-------- deal.II/examples/step-49/doc/results.dox | 8 +--- 2 files changed, 38 insertions(+), 25 deletions(-) diff --git a/deal.II/examples/step-49/doc/intro.dox b/deal.II/examples/step-49/doc/intro.dox index c77e3f506c..c9da6be05e 100644 --- a/deal.II/examples/step-49/doc/intro.dox +++ b/deal.II/examples/step-49/doc/intro.dox @@ -108,31 +108,41 @@ image (see the grid_1 function):

Modify a Mesh

-modify a mesh: - - merge meshes - - change boundary indicators - - move vertices - - transform via smooth function - - perturb/randomize mesh - - relax inner vertices? +After aquiring one (or several) meshes in the ways described above, there are +many ways to manipulate them before using them in a finite element +computation. -other things to mention: - GridTools::shift - GridTools::transform -GridTools::rotate - GridTools::scale +

Transformations

+The GridTools namespace contains a collection of small functions to transform +a given mesh in various ways. The usage of the functions GridTools::shift, +GridTools::rotate, GridTools::scale is fairly obvious, so we won't discuss +those functions here. -

Merge Meshes

+ GridTools::transform + - transform via smooth function + + - perturb/randomize mesh -use GridGenerator::merge_triangulations() -note, vertices have to match exactly. -example: +

Merge Meshes

+The function GridGenerator::merge_triangulations() allows you to merge two +given Triangulations into a single one. This only works, if the vertices of +the to be shared edge or face match exactly. It is useful to use +GridTools::shift and GridTools::scale to align the two meshes. In the +function grid_2() of this tutorial, we merge a square with a round hole +(generated with hyper_cube_with_cylindrical_hole()) and a rectangle. The +function GridTools::subdivided_hyper_rectangle() allows you to specify the +number of repetitions and the positions of the corners, this way we do not +need to shift it manually. You should inspect the mesh graphically to make +sure, that cells line up correctly and no hanging nodes exist in the merged +Triangulation. + +These are the input meshes and the output mesh:
@@ -149,10 +159,12 @@ example:
-

Move Vertices

-move individual vertices, first identify cells/vertices +The function grid_3() demonstrates the ability to pick individual vertices and +move them around in an existing mesh. Please be sure to not produce degenerate +cells. Here, we create a box with a cylindrical hole, that is not exactly +centered by moving the top vertices upwards: @@ -190,3 +202,10 @@ above. This is the output from grid_4():
+

Possible Extensions

+ +- Modify a mesh: + - change boundary indicators + - relax inner vertices +- Database of unstructured meshes for convergence studies + diff --git a/deal.II/examples/step-49/doc/results.dox b/deal.II/examples/step-49/doc/results.dox index 9e18b462df..cc5601ce56 100644 --- a/deal.II/examples/step-49/doc/results.dox +++ b/deal.II/examples/step-49/doc/results.dox @@ -1,9 +1,3 @@

Results

-The program has, after having been run, produced two grids, which look -like this: - - - -

Possible extensions

- +The program produces a series of .eps files of the Triangulations. The methods are discussed above. -- 2.39.5