> On Aug 26, 2016, at 2:15 PM, Justin Chang <jychan...@gmail.com> wrote: > > Hi all, > > When exactly would one need to modify the default restart value of 30 for > GMRES? I have seen papers like this which suggest playing around with values > between 1 and 30, but are there cases where people need to use large restart > values like 50 or 100?
Sure. It is not ideal because the work and memory requirements go up but if you have a problem where even after proper preconditioning there are say 50 "bad" eigenvalue/eigenvectors of the preconditioned operator then using a larger value is valid. Barry > > > Thanks, > Justin
