> El 28 dic 2016, a las 17:14, Vijay Gopal Chilkuri <[email protected]> > escribió: > > Dear Jose, > > Thanks for the references. > > I'm only calculation the smallest 10-100 eigenvalues using the krylovshur > algorithm. > > How important is it to use a preconditioner ? My matrix has at most 48 > nonzero elements per row. > >
With Krylov-Schur you don't need a preconditioner if computing smallest-real eigenvalues (which I think is your case). Preconditioners are relevant only for interior eigenvalues (chapter 3 of the users guide). Jose
