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Re: ConditionNumber

  • To: mathgroup at smc.vnet.net
  • Subject: [mg89514] Re: [mg89477] ConditionNumber
  • From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
  • Date: Wed, 11 Jun 2008 03:20:11 -0400 (EDT)
  • References: <200806101112.HAA18830@smc.vnet.net>

I think the LinearAlgebra package is now considered obsolete so I  
don't think it has been revised since version 5.2 (although I have not  
tried checking this). Anyway, I think the quickest way to compute the  
2-norm condition number of a matrix m is

With[{l = SingularValueList[m]}, First[l]/Last[l]] // N

Andrzej Kozlowski




On 10 Jun 2008, at 20:12, dh wrote:

>
>
> Hello,
>
> the entry in the manual about the condition number reads:
>
> "LinearAlgebra`MatrixConditionNumber[mat,Norm->p]  p-norm approximate
>
> condition number of a matrix, where p may be 1, 2, or \[Infinity]"
>
> In version 6.0.2, if you try: Norm->2 you get the message that only  
> 1 or
>
> Infinity is allowed.
>
> As the 2 norm is the most common norm, it is hard to see why it should
>
> not work.
>
> Daniel
>
>
>
>
>
> -- 
>
>
>
> Daniel Huber
>
> Metrohm Ltd.
>
> Oberdorfstr. 68
>
> CH-9100 Herisau
>
> Tel. +41 71 353 8585, Fax +41 71 353 8907
>
> E-Mail:<mailto:dh at metrohm.com>
>
> Internet:<http://www.metrohm.com>
>
>
>



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