On Mon, 25 Aug 2008, Jed Brown wrote: > It would be nice to store and manipulate the coordinates just like any > other Function. Suppose the basis operations accept (in some way) a > NULL coordinate vector which means that the element Jacobian is the > identity everywhere. That way you could manipulate mesh geometry by > evaluating forms to construct a new geometry Function. Then register > this new Function (i.e. compute associated element Jacobians, required > facet normals).
I agree it would be nice. But this function would need to feed into various routines, like Tabulate_Tensor. Would this just become part of the `w' coefficient vector? Or would there need to be another input to these routines? Or could the cell class contain this? I will have to think about it some more... - Shawn > Not all operations make sense without coordinates, but basis evaluation, > derivatives, and integration in the element interior still do. I think > treating the coordinates as a special case would duplicate a lot of > code. > > Of course in the pre- and post-processing you still need to be able to > handle `normal' mesh descriptions. For preprocessing, this means > projecting nodal coordinates into the finite element basis. They will > normally be exactly representable in the FE basis so an elementwise (DG) > projection would be sufficient (in the nodal case, it can just be > evaluation). Going the other way is just point evaluation (or a > continuous Galerkin projection). > > Thoughts? > > Jed _______________________________________________ DOLFIN-dev mailing list DOLFIN-dev@fenics.org http://www.fenics.org/mailman/listinfo/dolfin-dev
