On Apr 19, 2013, at 5:15 PM, Hui Zhang wrote: > I'm doing something like gasm.c. I can construct one VecScatte from comm to > each subcomm. But I can also construct VecScatter's from comm to the > processors in subcomm. Which mode do you think is good? Why? Thanks for > teaching me!
After reading the source codes, I think I mis-understood VecScatterCreate. There is no direct support for Scatter between comm and subcomm unless one of them is Seq (MPI_Comm_size == 1). Anyway, gasm.c provides a very good example for the 'MPI to MPI' (the same comm) Scatter. And asm.c provides that for 'MPI to Seq'. Learned a lot! Thanks for petsc's source codes!
