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Re: st: mean centering
From
David Hoaglin <[email protected]>
To
[email protected]
Subject
Re: st: mean centering
Date
Sun, 20 Jan 2013 20:56:44 -0500
The QR decomposition is not a panacea. If the matrix of predictor
variables is ill-conditioned enough, some loss of precision can still
result. We might do well to regard centering as preventive medicine.
David Hoaglin
On Sun, Jan 20, 2013 at 7:01 PM, Jvverkuilen <[email protected]> wrote:
> Yes, from what I recall from scientific computing, the QR decomposition solves the numerical problems. It effectively centers and orthogonalizes the variables.
>
> Centering is really about interpretation now.
>
> --
> JVerkuilen, PhD
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