Dear petsc-dev, I'd like to try out doing SOR-like smoothing for a problem with MG where on the pre-smooth I run forwards, and on the post-smooth backwards.
I can do this by setting up the PC and then spinning over the up and down smoothers separately. I wonder if it would be possible to extend the setup to allow it to be done from options. I had a look, but I got very lost in where/how the setup of the up smoother separate from the down smoother works. It seems to be triggered on whether you select a different number of smoothing steps up and down, but I don't necessarily want that. I think I just want to select a different options prefix in PCMGGetSmootherUp, but I can't obviously see how to ensure that's called appropriately. Cheers, Lawrence
