<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On May 28, 2012, at 5:29 PM, Jed Brown wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div class="gmail_quote">On Mon, May 28, 2012 at 10:25 AM, Hui Zhang <span dir="ltr"><<a href="mailto:mike.hui.zhang@hotmail.com" target="_blank">mike.hui.zhang@hotmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>But I'm not *changing* the operator. It is PCSetUp_Composite that call PCSetOperators on sub pc</div><div>a second time-- he does not know that the sub pc has been set up before.</div></blockquote></div><br><div>
Why do you call PCSetUp the first time?</div></blockquote><div><br></div><div>Because the PCComposite has two subpc's and one of the subpc is needed to be set up and used for </div><div>construction of the other subpc.</div><br><blockquote type="cite"><div><br></div><div>We don't currently have a mechanism to automatically know whether the operator has changed since the last setup, that's what the flag argument is for.</div>
</blockquote><br></div><div>Yes, I found this is a feasible way. I just set SAME_PRECONDITIONER for the PCComposite. </div><div>It is fine to me. Thanks!</div><br></body></html>