Thanks and what means if they are the same in ksp iterations?<br><br><div class="gmail_quote">On Tue, Oct 11, 2011 at 7:08 PM, Jed Brown <span dir="ltr"><<a href="mailto:jedbrown@mcs.anl.gov">jedbrown@mcs.anl.gov</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div class="gmail_quote"><div class="im">On Tue, Oct 11, 2011 at 10:33, behzad baghapour <span dir="ltr"><<a href="mailto:behzad.baghapour@gmail.com" target="_blank">behzad.baghapour@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
What is the difference between "unpreconditioned resid norm" </blockquote><div><br></div></div><div>This is estimated implicitly using the Krylov iteration. It can become inaccurate if the Krylov basis loses orthogonality (an issue of numerical stability).</div>
<div class="im">
<div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">and "true resid norm" in -ksp_monitor?</blockquote></div></div><br><div>This builds the residual explicitly. It is expensive with some methods, e.g. GMRES.</div>
</blockquote></div><br><br clear="all"><br>-- <br>==================================<br>Behzad Baghapour<br>Ph.D. Candidate, Mechecanical Engineering<br>University of Tehran, Tehran, Iran<br><a href="https://sites.google.com/site/behzadbaghapour" target="_blank">https://sites.google.com/site/behzadbaghapour</a><br>
Fax: 0098-21-88020741<br>==================================<br><br>