Dear Truong, My understanding is that the triangulation in deal.II works like a quad/oct-forest.That is, the mesh that is generated or read serves as the forest and each cell is a tree. Consequently, it is not possible to coarsen a mesh more than it's initial configuration.
For a lot of meshes generated by deal.II, this is not a problem since they contain a very low number of cells (for example, a cubic grid has 1 cell in it's coarsest level, hence it is a forest with once tree). However, if you read your mesh from an external source, you cannot make it coarser than it is when you have read it. My suggestions would be to make a coarse abacus mesh, then you refine it within deal.II. This way you would have a coarsest level with as few cell a possible, then you could refine it adaptively. As far as I know, it is not possible to coarsen a mesh below it's level 0, because this would imply "merging cell". I hope that was sufficiently clear. Best of luck! Bruno On Tuesday, August 31, 2021 at 9:26:32 a.m. UTC-4 truongthangp...@gmail.com wrote: > Hello everyone, > I am new to deal.II and I am playing around with the grid of L-shape which > is imported from Abaqus input file using GridIn::read_abaqus(). The grid > has been successfully read as well as the boundary indicators ( from the > surface with the name of "SS1" and "SS2"). However, when I try to do > coarsening the grid by setting cell->set_coarsen_flag(), nothing happened. > I also tested with adaptive refinement as in step-6, only a figure of the > new cell has been generated, none has been coarsened even I set the > coarsening ratio to high value. > I wonder what is wrong here or is there something that I misunderstand > with the code. Thanks in advance. > > [image: Capture.PNG] > [image: Capture.PNG] > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/e71f5ab4-b69e-49d0-8580-00d567938163n%40googlegroups.com.
