From: <HIDDEN>
Newsgroups: comp.soft-sys.matlab
Subject: Contradictory Rank
Date: Wed, 21 Mar 2012 02:38:37 +0000 (UTC)
Organization: The MathWorks, Inc.
Lines: 1
Message-ID: <jkbevd$cb7$>
Reply-To: <HIDDEN>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
X-Trace: 1332297517 12647 (21 Mar 2012 02:38:37 GMT)
NNTP-Posting-Date: Wed, 21 Mar 2012 02:38:37 +0000 (UTC)
X-Newsreader: MATLAB Central Newsreader 3384510
Xref: comp.soft-sys.matlab:761675

I have a diagonal matrix with values -3.4562e-14, 15.2673,  86.9550, 1.4873e+03. Matlab says that its rank is 3 and rref indicates the same. Why is this, and how can I figure out what's really going on?