PETSc vs HYPRE?
PETSc does a good job of giving us a suit of preconditioners and linear solvers (it has nonlinear solvers too). However in order to make it more efficient on large scale parallel linear problems, we need multigrid. PETSc do have multigrid but As Steve and Rajesh know, it’s a pain since our indexing scheme is different than theirs. And also we have to take care of some other coding stuff (we know cause we tried). I found hypre which has multigrid and some linear solvers, and the advantage is it is using the same indexing so the interface is very easy. This is just another option for users to choose what to use. We are still using PETSc for some of the matrix vector operation. You can say I’m just too lazy to code that up myself.
