On Apr 12, 2013, at 4:55 PM, Matthew Knepley wrote: > On Fri, Apr 12, 2013 at 9:44 AM, Hui Zhang <mike.hui.zhang at hotmail.com> > wrote: > Assembly of local Mat's to a parallel Mat formally defined by A = \sum_i Ri^T > Ai Ri. > > My Ai's are originally defined in sub-communicators. In Petsc, I was told > before there are no counterpart of Ri that can promote the mat Ai to > sup-communicator where A stays. (VecScatter can only acts on Vec but not Mat) > > So, what is the easiest way to achieve this task? Note that Ai's are already > defined in sub-communicators. > > What are you trying to do? Get the action of A, or assemble it directly?
Assembly it directly. I just found MatGetSubMatricesParallel. Maybe I can learn from the source codes of this function but I can not find where they are. > > Matt > > -- > What most experimenters take for granted before they begin their experiments > is infinitely more interesting than any results to which their experiments > lead. > -- Norbert Wiener
