On Fri, Jan 6, 2012 at 4:32 PM, Xuefeng Li <span dir="ltr"><<a href="mailto:li@loyno.edu">li@loyno.edu</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">
On Fri, 6 Jan 2012, Jed Brown wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
On Fri, Jan 6, 2012 at 16:18, Xuefeng Li <<a href="mailto:li@loyno.edu" target="_blank">li@loyno.edu</a>> wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
The stencil width of my DA to a DMMG object is<br>
created to be 1. It is later adjusted using<br>
DASetStencilWidth() to 2.<br>
<br>
</blockquote>
<br>
You are not supposed to do this.<br>
<br>
Either call DMDACreate2d() (or whichever dimension you want) or call the<br>
sequence<br>
<br>
</blockquote>
Understand.<br>
<br>
However, is there a way to change/adjust the stencil width<br>
AFTER the DA has been created and set up to a DMMG? Or,<br>
in general, can we attach different DA objects to a DMMG<br>
at different times?<br></blockquote><div><br></div><div>1) You cannot change this after setting up the DA. Just make another DA, since</div><div> they are very lightweight.</div><div><br></div><div>2) I think structuring new code around DMMG is wrong. It has been removed in</div>
<div> petsc-dev and is deprecated in 3.2. What are you trying to do?</div><div><br></div><div> Thanks,</div><div><br></div><div> Matt</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
ierr = DMDACreate(comm, da);CHKERRQ(ierr);<br>
ierr = DMDASetDim(*da, 2);CHKERRQ(ierr);<br>
ierr = DMDASetSizes(*da, M, N, 1);CHKERRQ(ierr);<br>
ierr = DMDASetNumProcs(*da, m, n, PETSC_DECIDE);CHKERRQ(ierr);<br>
ierr = DMDASetBoundaryType(*da, bx, by, DMDA_BOUNDARY_NONE);CHKERRQ(<u></u>ierr);<br>
ierr = DMDASetDof(*da, dof);CHKERRQ(ierr);<br>
ierr = DMDASetStencilType(*da, stencil_type);CHKERRQ(ierr);<br>
ierr = DMDASetStencilWidth(*da, s);CHKERRQ(ierr);<br>
ierr = DMDASetOwnershipRanges(*da, lx, ly, PETSC_NULL);CHKERRQ(ierr);<br>
ierr = DMSetFromOptions(*da);CHKERRQ(<u></u>ierr);<br>
ierr = DMSetUp(*da);CHKERRQ(ierr);<br>
<br>
<br>
I am updating all these functions now to give an error if you call them<br>
after DMSetUp().<br>
<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
DAGetInfo() confirmed<br>
that the stencil width is indeed 2. However,<br>
DAGetGhostCorners()/**<u></u>DAGetCorners() show that<br>
the ghost point width is 1, instead of 2.<br>
<br>
</blockquote>
<br>
</blockquote>
<br>
Regards,<br>
<br>
--Xuefeng Li, <a href="tel:%28504%29865-3340" value="+15048653340" target="_blank">(504)865-3340</a>(phone)<br>
Like floating clouds, the heart rests easy<br>
Like flowing water, the spirit stays free<br>
<a href="http://www.loyno.edu/~li/home" target="_blank">http://www.loyno.edu/~li/home</a><br>
New Orleans, Louisiana <a href="tel:%28504%29865-2051" value="+15048652051" target="_blank">(504)865-2051</a>(fax)<br>
<br>
</blockquote></div><br><br clear="all"><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>