Daniel, > In the time I have used deal.ii I have used it to solve 2D systems of > equations (x and y), and have not dealt with a third dimension. However, > I wish to augment the system of equations I solve with a 3D equation (x, > y, z), one which will only affect the 2D equations through the > z-integral of a three-dimensional field. (And I don't want to make the > 2D equation a trivially-3D one so that it can be solved on a 3D grid... > I don't think.) So basically I want to go back and forth between a 2D > and 3D grid.
Would it be correct to say then that your 2d mesh would be a single face of the extruded 3d mesh? > I was wondering if any tools existed in deal.ii that would > make this a little bit easier - for example, when working with the 3D > grid, a way to get a reference to the cell which is its projection in > the x-y plane. If you work with the svn repository rather than the last release, then there is a function GridTools::extract_boundary_mesh that could give you the 2d mesh given the 3d mesh, along with a mapping from one to the other. That might make your life marginally simpler. To facilitate the mapping from 3d cells to 2d cell, you may wish to keep a vector<Triangulation<2>::active_cell_iterator> with all the cells of the 2d mesh somewhere, and use the user_pointer field of the cell iterators of your 3d mesh to store pointers into this array. > Or a quick way to populate a 2D vector with the > z-integral of a 3D field. I think I see a way to do things like this > "manually", but it may be slow and has the potential for dozens and > dozens of bugs. I don't think we have anything like this right now. Best W. ------------------------------------------------------------------------- Wolfgang Bangerth email: [email protected] www: http://www.math.tamu.edu/~bangerth/ _______________________________________________ dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii
