[R] Eigenvectors and values in R and SAS

[David Winsemius]

On Jan 11, 2010, at 2:31 PM, jso717 wrote:

>
> Hi,
>
> I was wondering if function eigen() does something different from the
> function call eigen() in SAS.
> I'm in the process of translating a SAS code into a R code and the  
> values of
> the eigenvectors and eigenvalues of a square matrix came out to be  
> different
> from the values in SAS.

Examples?

Were you under the impression that eigenvectors and eigenvalues were  
uniquely determined? You should review your matrix algebra. The  
question should be whether they are the same (still modulo sign) after  
normalization.

> I would also appreciate it if someone can explain the difference in  
> simple
> terms. I'm pretty new to both programs. Thanks for your help-
> -- 

David Winsemius, MD
Heritage Laboratories
West Hartford, CT