PETSc block matrix structure and field split preconditioners

[jcc242]

Hello,

I am intersted in using a field split preconditioner with PETSc for a coupled solve of two equations. My understanding is this would be best done using PETSc's block matrix structure, however the RheoTool manual Sec. 4.5.10 says that the coupled solvers are not using the block matrix structures of PETSc.

Are there any roadblocks on switching to the block matrix structures? I am thinking of trying to implement that in RheoTool very soon. Any thoughts or guidance?

Thank you,
Joshua