> On Mar 7, 2017, at 9:41 PM, Fande Kong <[email protected]> wrote: > > > > On Tue, Mar 7, 2017 at 7:37 PM, Barry Smith <[email protected]> wrote: > > > On Mar 7, 2017, at 4:35 PM, Kong, Fande <[email protected]> wrote: > > > > I found one issue on my side. The preallocation is not right for the BAIJ > > matrix. Will this slow down MatLUFactor and MatSolve? > > No, but you should still fix it. > > > > > How to converge AIJ to BAIJ using a command-line option? > > Instead of using MatCreateSeq/MPIAIJ() at the command line you would use > > MatCreate() > MatSetSizes() > MatSetBlockSize() > MatSetFromOptions() > > MatSetFromOptions() has to be called before "MatXXXXSetPreallocation"? What > happens if I call MatSetFromOptions() right after "MatXXXXSetPreallocation"?
To late! The type has to be set before the preallocation, otherwise the preallocation is ignored. Note there is a a MatXAIJSetPreallocation() that works for both AIJ and BAIJ matrices in one line. > > MatMPIAIJSetPreallocation() > MatMPIBAIJSetPreallocation() and any other preallocations you want > MatSetValues.....MatAssemblyBegin/End() > > Then you can use -mat_type baij or aij to set the type. > > Barry > > > > > Fande, > > > > On Tue, Mar 7, 2017 at 3:26 PM, Jed Brown <[email protected]> wrote: > > "Kong, Fande" <[email protected]> writes: > > > > > On Tue, Mar 7, 2017 at 3:16 PM, Jed Brown <[email protected]> wrote: > > > > > >> Hong <[email protected]> writes: > > >> > > >> > Fande, > > >> > Got it. Below are what I get: > > >> > > >> Is Fande using ILU(0) or ILU(k)? (And I think it should be possible to > > >> get a somewhat larger benefit.) > > >> > > > > > > > > > I am using ILU(0). Will it be much better to use ILU(k>0)? > > > > It'll be slower, but might converge faster. You asked about ILU(k) so I > > assumed you were interested in k>0. > > > >
