[petsc-users] precise meaning of SAME_NONZERO_PATTERN in MatAXPY?

[Frederik Treue]

Hi,

what, exactly, does the the matstructure parameter to (e.g.) MatAXPY do?
If the two matrices come from the same dm, ie. have the same stencil, is
SAME_NONZERO_PATTERN then _guaranteed_ to work? Or does the routines
actually depend on the actual value of the matrices being zero/non-zero,
even inside the stencil?

/Frederik Treue