On Sun, Jun 29, 2008 at 09:03:07PM +0200, Dag Lindbo wrote: > > 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.
I don't remember this. I must have just forgotten about the patch. Send it again. There is support in UFC (utils) for generating separate .cpp and header files. -- Anders > 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
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