On Mar 9, 2012, at 12:34 PM, Jed Brown wrote: > On Fri, Mar 9, 2012 at 11:05, Barry Smith <bsmith at mcs.anl.gov> wrote: > Here is the problem. We cannot use LSC with user provided L (and Lp) and > PCFIELDSPLIT now AT ALL!! That sucks, maybe we shouldn't be looking for a > perfect solution but for now just one that works somewhat! > > Yup, this is why I still have hacks that implement MatGetSubMatrix() to pass > this stuff around. I'll follow your suggestion here. How urgent is this?
Matt is breathing down my neck here in DC. Barry > > > > I will suggest the following approach. Attach various L to the original > Jacobian with a different name for each. In your case L_displacement and > L_pressure, have PCFIELDSPLIT propagate them to the Schur matrix. Then have > -prefixfromfieldsplit_pc_type lsc -prefixfromfieldplit_lsc_name > L_displacement to tell LSC which one to use. > > Barry > > Not perfect since the user could name the wrong lsc for the Schur index sets > used but it is better than nothing. >
