Dear Martin, first, thank-you for your help.
Really I don't know what to do between these possibilities: 1) Using TrilinosWrappers::PreconditionStokes Class (http://www.dealii.org/developer/doxygen/deal.II/classTrilinosWrappers_1_1PreconditionStokes.html). This implies to download, configure and rebuild the subversion of DealII. Now I am using the version 6.1.0. Besides, if you tell me that perhaps there are some bugs working with NS... 2) Following tutorial step-20 (http://www.dealii.org/6.1.0/doxygen/tutorial/index.html). Taking into account that I am working with NS and that M will be not symmetric. This case allows me to use version 6.1.0, that is the present version I have installed. 3) Or, as it is shown at the end of the tutorial step-20 to use PreconditionLACSolver (http://www.dealii.org/6.1.0/doxygen/deal.II/classPreconditionLACSolver.html) as InverseMatrix and SchurMatrix (http://www.dealii.org/6.1.0/doxygen/deal.II/classSchurMatrix.html) as Schur complement. This case allows me to use version 6.1.0, that is the present version I have installed. What option do you think is the best one? Any advice will be welcome. Best Isa Martin Kronbichler wrote: > Dear Isabel, > >> so I mean I would have to use "TrilinosWrappers::PreconditionStokes >> Class", wouldn't I? >> >> And this class is in the developing part of the library DealII, isn't >> it? > > Yes, you can give it a try (but I'm not sure whether this class will > remain in the library in the current form also in the future, since it > is very specific, whereas the library is rather meant to be general). > > As the author of that piece of code I have to admit that it is not > really tested (actually I only tested the Stokes part rigorously, but > not the necessary changes for Navier-Stokes, so I'm pretty sure there > still are some bugs). You will need to have the matrix in > TrilinosWrappers::BlockSparseMatrix format and the vector as > TrilinosWrappers::BlockVector. And then there need to be some more > matrices around, like a pressure mass, Laplace and convection-diffusion > matrix (the last one you build just as the Navier-Stokes velocity > matrix, but on the scalar pressure space)... > > So just try it and report me any problems! > > Best, > Martin > _______________________________________________
