On Wed, Feb 25, 2015 at 12:13:15PM -0500, Mark Adams wrote: > > > > > > > > MatProjectDirichlet() would be useful here, too: it would allow the > > user to inject the right modifications to the near nullspace. > > > > I'm not sure this is a good abstraction. These are coordinate > transformations. Here you just want to know if the value should be zero > but in general you want a real transformation. > > If the user rotates the local coordinate system to match the BC and zeros > out row(s) then there will be a dummy equation and you should, in theory, > rotate the null space, and the dumb MatProjectDirichlet do its job. If the > user _then_ rotates the operator back (what you initially suggested I > think) then I don't think you need to do anything, now that I think about > it.
I see your point. Any users with local coordinate rotations for Dirichlet conditions can probably provide their own near nullspace.
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