Normally they need to be the same, but not always. For KSPLSQR the A matrix may
be rectangular but the B matrix is A^TA which is square. This special case is
why we don't do error checking.
Barry
> On Apr 16, 2018, at 1:04 PM, Alp Dener <[email protected]> wrote:
>
> Hi Barry,
>
> While I was working on some active-set related stuff in TAO, I discovered
> that I can call KSPSetOperators() with differently sized Mat and PC objects
> without getting any errors or warnings about the size mismatch. Note that my
> Mat object is explicit, but the PC object is a MATSHELL. Is this intended
> behavior, or is it a bug?
>
> —
> Alp Dener
