On Wed, Feb 11, 2009 at 1:46 PM, Yixun Liu <span dir="ltr"><<a href="mailto:enjoywm@cs.wm.edu">enjoywm@cs.wm.edu</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Hi,<br>
In ksp/ex2.c<br>
<br>
/*<br>
Set operators. Here the matrix that defines the linear system<br>
also serves as the preconditioning matrix.<br>
*/<br>
ierr = KSPSetOperators(ksp,A,A,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr);<br>
<br>
The matrix related with linear system is same with the preconditioning<br>
matrix, why set the flat to be DIFFERENT_NONZERO_PATTERN?</blockquote><div><br>This flag has to do with whether the PC is reformed. There is a section in the manual on this.<br><br> Matt<br> </div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br>
Thanks.<br>
</blockquote></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>