From: Roy Stogner <roystgnr@ic...>  20110209 17:26:12

On Fri, 4 Feb 2011, Saurabh Srivastava wrote: > I looked into the file and quite worried about this implementation, have you > followed any particular implementation of Hierarchics on triangles? I > presume the triangles are not trivial tensor product based and so analytical > derivatives are good effort to compute.. can you give me some > tips/references on what polynomials are used and how? No, but I'll Cc: this to libmeshdevel  I think it was Ben or John who put in the shape function implementations and hopefully they'll have a reference you could look at to make it easier to calculate derivatives. > I am also wondering how to statically link the library(both petsc and > libmesh) to my code?, based on the perflog I see that most of the time is > spent in linear solvers, which in a way is a good happening ... although it > takes few thousand iterations for only one linear solve / iteration/ time > step ..since conditioning is quite poor..but there might be issue due to > time spent in linking on the fly for those thousand iterations? Nope  the cost of dynamic linking is pretty much all at the very start of run time when the linking is done. > I would like to use a parallel direct solver from petsc which I have > compiled with full set of solvers, umfpack, superlu etc.. but the command > line argument mat_type superlu etc. all throw an error in petsc 3.1.4 as > unrecognized, so what is the command line way to use a parallel sparse > direct solver in libmesh? Off the top of my head: use the direct solver as a "preconditioner"; the Krylov loop will then terminate with a single iteration and you can replace GMRES with Richardson or something simple. You might want to check the performance of ILU4 or something intermediate before taking such a drastic step, though.  Roy 