what kind of Pivoting does QRDecomposition use
- To: mathgroup at smc.vnet.net
- Subject: [mg54556] what kind of Pivoting does QRDecomposition use
- From: "chiCong" <chicong.v at gmail.com>
- Date: Tue, 22 Feb 2005 04:26:07 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Hello, Can someone tell me what kind of Pivoting does QRDecomposition use when I specify [qq,rr,ee]=QRDecomposition[mm,Pivoting->True]; Mathematica document says that ee is a permutation "such that" mm.ee == Transpose[qq].rr but nothing more. Especially, I want to have rr with decreasing diagonal elements (like the way another system does it by the command "qr"). It seems that Pivoting->True doesn't work that way. Regards, Cong