Pierre, https://bitbucket.org/petsc/petsc/pull-requests/809/only-propagate-operators-into-inner-pcs-in/diff
Sorry for the long delay in responding. Barry > On Nov 10, 2017, at 1:36 PM, Jed Brown <j...@jedbrown.org> wrote: > > "Smith, Barry F." <bsm...@mcs.anl.gov> writes: > >>> On Nov 9, 2017, at 11:13 PM, Jed Brown <j...@jedbrown.org> wrote: >>> >>> "Smith, Barry F." <bsm...@mcs.anl.gov> writes: >>> >>>> Jed, >>>> >>>> Please articulate in a bit more detail. From what I can interpolate you >>>> are saying >>>> >>>> 1) that if we only propagate the outer matrices to inner matrices that the >>>> user has not set we will get a better more intuitive interface for users >>>> >>>> but >>>> >>>> 2) the whole idea of propagating in is probably flawed. >>> >>> The idea of having only two matrices, Amat and Pmat, is flawed. >> >> Yes >> >>> A >>> composite preconditioner, for example, may need more. Having users >>> unwrap solvers to manually set matrices is ugly, but in lieu of a better >>> way (like named auxiliary matrices that can be requested by nested >>> preconditioners), we should honor the user's manual choices. >> >> Yes. >> >> But you are not directly answering my question. Should we change >> the code to not propagate if already set? > > Yes, I think so. That is what I meant by "we should honor the user's > manual choices" above.