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From: "Nasser M. Abbasi" <nma@12000.org>
Newsgroups: comp.lang.ada
Subject: Re: ANN: Ada 2005 Math Extensions 20120712
Date: Sun, 29 Jul 2012 09:22:46 -0500
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Date: 2012-07-29T09:22:46-05:00
List-Id: <comp.lang.ada>

On 7/29/2012 9:05 AM, Ada novice wrote:
> On Saturday, July 28, 2012 8:33:32 PM UTC+1, Simon Wright wrote:
>

> I've read that ACML is developed with NAG and so getting different results was
>perhaps not something to be expected. Eigenvectors are tricky as they could be
>normalised or not and different normalisation schemes exist. Something would
>have been terribly wrong had the eigenvalues were different!
>
> YC
>

It is the other way around.

Eigenvector times a scalar is still a valid Eigenvector.
(i.e. scaling an eigenvector does not matter).

But if the sign of the eigenvalue is different, then you
need to look into it. Depending on the context, eigenvalue
sign indicate stability or not. So it is important.

--Nasser