Barry Smith <bsm...@mcs.anl.gov> writes: > How about fixing this? Agreed we should not be requiring people to > use MatShell to do this stuff but it sounds you want to work around > a current design flaw with PCMG by using PCMGSetResidual. Why not > fix the design flaw?
What is the "correct" way to compute coarse operators when the user wants part Galerkin and part rediscretization? The user's (non-Galerkin) matrix assembly function has both Mat slots, and they'll need to know which one to ignore when PCMG configuration says to make one or the other Galerkin. I don't know what is really a good interface for this. PCMGSetResidual doesn't seem that inconvenient to me. (Sure, it's not as nicely recursive and nestable as you might like in an idealized world, but matrix-free MG implementations for real problems usually have lots of constraints anyway.)
pgpDEl0J9Sf4j.pgp
Description: PGP signature
