Dear Matt, > This does not make sense to me. You decide how PETSc partitions things (if > you want), And, I really do not understand what you want in parallel. > If you mean > that you solve the local Schur complements independently, then use a local > matrix for each one. The important thing is to work out the linear > algebra prior > to coding. Then wrapping it with PETSc Mat/Vec is easy.
The linear algebra is completely clear. Again: I have the local Schur systems given (and NOT the solution of the local Schur systems), and I would like to solve the global Schur complement system in parallel. The global Schur complement system is theoretically constructed by putting and adding elements of the local systems in certain locations of a global matrix. Wrapping this with PETSc Mat/Vec, without the time-intensive assembling, is not easy for me as a PETSc-beginner. But I'm curious of the solution you propose...
