> Hello! > > I tried to compile an advection diffusion form using Streamline Upwind > Petrow > Galerkin stabilazing method, similar to the one introduced in DOLFIN > 0.6.4. > Using 3 dimensional and first degree Lagrange elements, FFC/g++ chokes > when > the produced code is compiling. It wont finish compile... Is this a known > problem and a limitation of FFC/g++?
I worked a bit with this kind of form and also had impossibly long compilation times (back in the 0.6.4 day). The solution then was to compile the implementation of the form into a separate object. In order to do this I made a patch for FFC so that it emit the implementation in a separate file from the declarations. Then the form could be compiled once (often over lunch) instead of each time I tweaked the solver code. Also, I had then the option to build the form implementation with less optimization (which made a huge difference). However, my patch for FFC was never taken in. No hard feelings over this, but I still think it is a worthwhile option. Another C++ approach to this compile-form-once problem is to wrap it in a "factory" class and build that one with less optimization. Form compilation times have improved though :) /Dag > > In PyCC I use DOLFIN to assemble the same system matrix, but instead of > using > one form for the whole system I split the form into at least 4 different > forms. These compiles smoothly and after I have assembled the matrices I > just > add them together. > > This approach is not possible using the present DOLFIN linear algebra > interface, as sum of matrices is not supported. Is this something we want > for > the future? > > Johan > _______________________________________________ > DOLFIN-dev mailing list > [email protected] > http://www.fenics.org/mailman/listinfo/dolfin-dev > _______________________________________________ DOLFIN-dev mailing list [email protected] http://www.fenics.org/mailman/listinfo/dolfin-dev
