I am new to R. So I posted the program I wrote so I can get help on where it
is going wrong and if I could approach it using the Sylvesters criterion and
why it comes up with an error when I use the eigenvalues. The matrices I
provided are generated randomly the purpose of my question is not any
interpretation just a guidance to why I get an error and how to fix that or
use the Sylvesters criterion.

Thank you

On Tue, Feb 1, 2011 at 5:25 PM, Mike Marchywka <marchywka@hotmail.com>wrote:

>
>
>
>
> >Date: Tue, 1 Feb 2011 15:41:01 +0000
> >From: alex.smit4@gmail.com
> >To: spencer.graves@structuremonitoring.com
> >CC: r-help@r-project.org; maechler@stat.math.ethz.ch
> >Subject: Re: [R] Positive Definite Matrix
>
>
> >Hello thank you for so much input. I am afraid that I am fairly new to
> this
> and some of the material is above my understanding for the time being and I
> am not looking at anything very complex as you will see from the program I
> will include.
> I have been talking to a fellow colleague I am working with and have come
> down to this.
> Your input has been invaluable to me learning more about R thank you!
> 1.As an example, I do not wish to find a near pd matrix but I want to test
> wether it is pd or not so I know if I want it or not,as you will see on the
> program I want two outputs depending on if it is a pd and symmetric. So I
> have written this for one symmetric matrix and it works and one for a non
> symmetric one slightly changed but it doesnt work,if you could point out
> why
> this is going wrong that would be helpful. It cant compare the complex
> eigenvalues.
> [...]
>
> >2. My colleague said why dont we use the Sylvester's Criterion and test
> the
> leading minors. Would something like that work?
>
>
> This thread seems to have dragged on for a while, what are you trying to
> do?
> Presumably this is something other than an exercize in R.
> What interpretation do you have for your eignenvalue spectrum or matrix
> element
> ? Problems here could point to various features or pathologies or
> opportunities at various points in the analysis.
>
>
>
>
>

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