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.
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