<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div> If you do want to do this with a dense matrix then just use MatGetArray() to directly access the matrix entries. Then you can skip the MatGetColumn() and MatSetValues() stuff.<div>But I agree with Matt that generally if you are doing orthogonalization it is a set of vectors you are doing it to. You then decide if you want to represent that collection of vectors as a dense matrix (which is the Matlab way) or as an array of vectors.</div><div><br></div><div> Barry</div><div><br><div><div>On May 18, 2010, at 4:08 AM, Matthew Knepley wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">On Tue, May 18, 2010 at 3:58 AM, Umut Tabak <span dir="ltr"><<a href="mailto:u.tabak@tudelft.nl">u.tabak@tudelft.nl</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;">
<div class="im">Matthew Knepley wrote:<br>
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1) This must be a dense matrix, so you could directly copy in the values with a strided loop<br>
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Dear Matt,<br>
Thanks for the immediate reply, I guess I did not understand this.<div class="im"><br>
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2) Is there a reason for the output to be a matrix, rather than a collection of vectors?<br>
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Collection of vectors? not sure on this point. After the orthogonalization, I extract some parts of the matrix and continue operation with these extracted parts. Are there better ways of conducting operations for these kinds of tasks?<br>
</blockquote></div><br>Well, you generally do not want the parallel organization of a MPIDENSE when you make<div>these sorts of updates. You want to access 1 column at a time, with the layout of a vector.</div><div>Thus is generally makes more sense to me to use a Vec[] than a MPIDENSE.</div>
<div><br></div><div> Matt<br clear="all"><br>-- <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>
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