Thank you, Jed. "-snes_compare_explicit" worked with a nested matrix. I'll try to use MatGetLocalSubMatrix in my programm.
Best, nori On Thu, Apr 17, 2014 at 4:56 PM, Jed Brown <[email protected]> wrote: > Norihiro Watanabe <[email protected]> writes: > > > Hi, I wonder whether "-snes_type test" option can work also with a nested > > matrix. I got the following error in my program and am not sure if there > is > > a problem in my codes or just PETSc doesn't support it. > > I believe -snes_compare_explicit should convert if necessary (it > provides similar functionality to -snes_type test). > > > Testing hand-coded Jacobian, if the ratio is > > O(1.e-8), the hand-coded Jacobian is probably correct. > > Run with -snes_test_display to show difference > > of hand-coded and finite difference Jacobian. > > [0]PETSC ERROR: --------------------- Error Message > > ------------------------------------ > > [0]PETSC ERROR: No support for this operation for this object type! > > [0]PETSC ERROR: Mat type nest! > > We strongly recommend writing your code in a way that is agnostic to > matrix format (i.e., assemble using MatGetLocalSubMatrix). Then just > use a monolithic format for comparisons like this and switch to MatNest > when trying to get the best performance out of a fieldsplit > preconditioner. > -- Norihiro Watanabe
