<div class="gmail_quote">On Tue, Nov 9, 2010 at 12:11, Tim Kroeger <span dir="ltr"><<a href="mailto:tim.kroeger@cevis.uni-bremen.de">tim.kroeger@cevis.uni-bremen.de</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div id=":372">Is it allowed to work with an index set (IS) with size 0?<br></div></blockquote><div><br></div><div>Yes.</div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div id=":372">
In particular, using such an index set in VecScatter and MatGetSubMatrix, I am creating the following objects:<br>
<br>
v : a vector of size n>0,<br>
w : a vector of size 0,<br>
A : a matrix of size n\times0.<br>
<br>
Then I do<br>
<br>
MatMultAdd (A, w, v, v);<br>
<br>
This actually seems to change the value of v, although I supposed it not to do so.<br></div></blockquote><div><br></div><div>It sounds like you have a simple test case for this, could you send it?</div><div><br></div><div>
Jed </div></div><br>