<div>Thanks Jed. </div>
<div> </div>
<div>And in the term ||Ae||/||Ax||, PETSc impilictly assume that we use zero as initial guess and here the x really means exact solution, right?</div>
<div> </div>
<div>Yan</div>
<div> </div>
<div><br><br> </div>
<div class="gmail_quote">On Tue, Sep 15, 2009 at 6:41 PM, Jed Brown <span dir="ltr"><<a href="mailto:jed@59a2.org" target="_blank">jed@59a2.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">
<div>Ryan Yan wrote:<br>> But can you say a little more about what happened in the first scenario, I<br>> did not quite fellow you. Let's say, If I set -ksp_rtol 1e-2, what does this<br>> mean in the left PC case. More specifically, which term will be considered<br>
> as a stop creteria for the KSP solve.<br><br></div>Look at the first column (preconditioned residual norm). Notice that<br>this is decreasing by 1e-2 and 1e-3 respectively in your examples.<br><font color="#888888"><br>
Jed<br><br></font></blockquote></div><br>