Dear Guys, I have quick question for you. Can anyone tell me if MatDiagonalSet needs also MatAssemblyBegin/MatAssemblyEnd to be called afterwards or not?
Basically, I am trying to compute: sum (a_nb*\phi_nb), where anb are the off diagonal coeffs of the matrix and phi_nb the corresponding field values. I was thinking to set the matrix diagonal to zero using MatDiagonalSet and then simply use MatMult(A, x) to accomplish my task. Do we have a better way in PETSc? Any suggestion in welcome :) Thank you very much
