On Fri, Aug 31, 2012 at 1:04 PM, Chris Eldred <span dir="ltr">&lt;<a href="mailto:chris.eldred@gmail.com" target="_blank">chris.eldred@gmail.com</a>&gt;</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">
I was wondering how components were treated in PetscSection- my<br>
understanding is that a field with multiple components and multiple<br>
dofs would have those dofs duplicated for each component, but that<br>
does not appear to be the case. For example, let&#39;s say I have a field<br>
with 2 components and 2 dofs that covers 10 points. I expected that it<br>
would have size 40: 4 dofs per point x 10 points. Instead, it appears<br>
to have size 20: 2 dofs x 10 pts.<br></blockquote><div><br></div><div>Yep, that is not the case. What if the components are discretized with</div><div>different numbers of dofs on different points? This definitely happens.</div>
<div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
What then are components in PetscSection- is it just a way of telling<br>
the code that the dofs associated with a field at a point are really<br>
split across multiple components (ie for my example, I should define 4<br>
dofs at each pt instead of 2)? How does that then interact with the<br>
re-ordering done in DMComplexVecGetClosure?</blockquote><div><br></div><div>The idea of components is to give you an idea what kind of field you are</div><div>dealing with. I know I don&#39;t go so far as to tell you its a vector, or a</div>
<div>pseudo-vector, etc. I am not sure where to draw the line yet. Within</div><div>GetClosure(), the dofs for reversed points are separately reversed per</div><div>component.</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"><span class="HOEnZb"><font color="#888888"><br>
--<br>
Chris Eldred<br>
DOE Computational Science Graduate Fellow<br>
Graduate Student, Atmospheric Science, Colorado State University<br>
B.S. Applied Computational Physics, Carnegie Mellon University, 2009<br>
<a href="mailto:chris.eldred@gmail.com">chris.eldred@gmail.com</a><br>
</font></span></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>