Unique QR decomposition
- To: mathgroup at smc.vnet.net
 - Subject: [mg131384] Unique QR decomposition
 - From: mpressprich at gmail.com
 - Date: Wed, 17 Jul 2013 01:49:23 -0400 (EDT)
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I am a Mathematica beginner. I ran QRDecomposition on an invertible matrix and got negative diagonal elements in the R matrix. How do I get Mathematica to return all positive diagonal elements for R? According to Golub & Van Loan this should be possible and guarantees a unique solution. (I naively assumed that Mathematica would do this automatically.)