[petsc-users] MatCreateSchurComplementPmat to create a Schur complement

Hi, When I use the MatCreateSchurComplementPmat to create a Schur complement for my own usage, I do not understand the logic when preuse=MAT_INITIAL_MATRIX. If all the matrixes are not empty, the first thing it did is 809: MatDestroy(Spmat); So that means I cannot pass in an empty matrix. It works if I first do MatCreate a dummy matrix and then pass in. Is that just some inconsistency or is there something I misunderstood? Qi