"Smith, Barry F." <bsm...@mcs.anl.gov> writes: > Sorry, my mistake. I assumed that the naming would follow PETSc convention > and there would be MatGetLocalSubMatrix_something() as there is > MatGetLocalSubMatrix_IS() and MatGetLocalSubMatrix_Nest(). Instead > MatGetLocalSubMatrix() is hardwired to call MatCreateLocalRef() if the > method is not provide for the original matrix. > > Now interestingly MatCreateLocalRef() has its own manual page which states: > Most will use MatGetLocalSubMatrix(). I am not sure why MatCreateLocalRef() > is a public function (that is why it would ever be called directly). Perhaps > a note could be added to its manual page indicating why it is public. My > inclination would be to make it private and call it > MatGetLocalSubMatrix_Basic(). There is harm in having multiple similar public > functions unless there is a true need for them.
I think the motivation was that it's actually a Mat implementation and thus made sense as Developer level interface rather than a strictly internal interface. I don't know if we had in mind any use cases where it could be useful to a general caller. I don't have a strong opinion at the moment about whether it makes sense to keep like this or make internal.
