Dear PETSc -- This is most embarassing, but somehow I can't see it in the docs.
Regarding defaults for DMDA and PCMG, for the fine-to-coarse restriction, does -pc_type mg use the adjoint of interpolation? (I.e. "full weighting," at least up to a constant.) Or is an injection used? I see that in src/dm/impls/da/dainterp.c, both (Q1,Q0) interpolation and some injection are _implemented_ for DMDA. But I don't see what is used by default, or how to control it at the command line. Asking for options related to my question is a bit of a dead end. For example, in src/snes/examples/tutorials/, ./ex5 -da_refine 3 -pc_type mg -help | grep XX returns nothing at all for XX=injection,restriction,interpolation. Would a new option -pc_mg_restriction_type transpose|injection make sense? Thanks, Ed -- Ed Bueler Dept of Math and Stat and Geophysical Institute University of Alaska Fairbanks Fairbanks, AK 99775-6660 301C Chapman
