[petsc-dev] DMPlexMarkBoundaryFaces is quadratic time

[Jed Brown]

Matthew Knepley <knepley at gmail.com> writes:
> Why is it quadratic time? I just looked again, and it seems to be linear
> time to me.

Look at DMLabelSetValue().  If the point is not labeled yet
(PetscFindInt returns negative) then you call PetscMemmove(), which is
linear complexity in general.  It's not really quadratic because these
faces all come in order, but it could have a whomping big constant if
that label had already been used for other points with a higher value.
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