On Thu, Dec 22, 2011 at 7:51 PM, Jed Brown <span dir="ltr"><<a href="mailto:jedbrown@mcs.anl.gov">jedbrown@mcs.anl.gov</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="gmail_quote">On Thu, Dec 22, 2011 at 19:46, Matthew Knepley <span dir="ltr"><<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
dtol failure is impossible for GMRES (and CG). Consider checking with that.</blockquote></div><br><div>Well, if you turn of restarts in GMRES and if orthogonalization is working correctly.</div>
</blockquote></div><br>Even if you lose orthogonality, it will just stagnate since you always have the solution<div>from the first few vectors. Likewise, I do not see how you can get an diverging sequence</div><div>from restarting since you always have the last residual, you just stagnate.<br clear="all">
<div><br></div><div> Matt</div><div><br></div>-- <br>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>-- Norbert Wiener<br>
</div>