On Thu, Aug 4, 2016 at 2:43 AM, Mark Adams <[email protected]> wrote: > We are pushing the bounds of -snes_fd and I wanted to understand what > we can expect. We do not use a DM. I assume FD has to apply the > operator N times. I don't see how you can color unless we give SNES a > graph (in a DM). Am I missing something? >
Nope, it needs some idea of connectivity to color. > If not, I could construct a symmetric matrix that would be, I think, a > "safe" graph to use for coloring. Is there an method (or example code) > to get SNES to use that for a coloring? Like a DM constructor that > takes a graph in a Mat. > Okay, there is -snes_fd_color -snes_fd_color_use_mat -mat_coloring_type greedy which takes a properly preallocated matrix. 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
