2008/8/20 Anders Logg <[EMAIL PROTECTED]>: > On Wed, Aug 20, 2008 at 08:43:08AM -0600, Ostien, Jakob T wrote: >> Hi, >> >> I need to be able to assemble an active set of integration points. >> Essentially, to determine the set I loop over cells and then loop again over >> the integration points in the cell and determine if that integration point >> is active with some criteria. Then I'd like to be able to assemble that set. >> >> This is a problem because currently the element_tensor does not break down >> into integration points, and I need to take derivatives, so the >> QuadratureElement in FFC is also ruled out. I suppose I could calculate >> derivatives and then project on the QuadratureElement, but that seems sort >> of unclean. >> >> It seems like the recent discussion about integrating at a point (on the UFC >> list) might help me out here. >> >> Any other thoughts on how I might go about this? >> >> Jake > > I don't know yet. I'm thinking about how much of this should go into > the compiler and how much should be left to the user. > > We're working on similar things (and I know Garth is too). I think a > common denominator would at least be to be able to evaluate a form at > a given point. > > I like Kent's suggestion earlier about adding a new UFC class to go > along with the other three integral classes, something like > > point_integral > > with tabulate_tensor taking the coordinates for a point as additional > input. > > -- > Anders
I liked your version with adding a new function to each *_integral class better. The reason is that each *_integral object will correspond to one foo*dx(i) or bar*ds(j) in the form definition, and each *_integral object will be able to compute both an integral over some cell and the corresponding integrand. Although a separate point_integral might make sense for something I don't know about, matching them to corresponding cell_integral, exterior_facet_integral and interior_facet_integral objects will become messy. -- Martin _______________________________________________ DOLFIN-dev mailing list [email protected] http://www.fenics.org/mailman/listinfo/dolfin-dev
