I’m trying to get a handle on the different ways of constructing matrices. Currently, I have:
MatCreate(...) MatSetSizes(...) MatSetFromOptions(...) MatSetUp(…) but I gather from reading the manual that, by not preallocating, I’m losing out in performance. If I assume that my matrix will either by SeqAIJ or MPIAIJ, depending on the number of processors available, how would I go about doing this. I see some of the example codes with: MatSeqAIJSetPreallocation(…) MatMPIAIJSetPreallocation(…) as successive commands. Should I interpret this as saying that PETSc will just ignore the one that is not the active one in the current instance? -gideon
