[R] R conversion

[John Fox]

Dear Mark, 

> -----Original Message-----
> From: Mark Strivens [mailto:mstrivens at houston.rr.com] 
> Sent: Thursday, September 09, 2004 9:52 PM
> To: John Fox
> Cc: r-help at stat.math.ethz.ch
> Subject: Re: [R] R conversion
> 
> Thanks John for the post - I had found factanal However 
> factanal it seems you have specify the number of factors to 
> be fitted up front, whereas with the SAS procedure you don't 
> - this is apparently important to the analysis!
> 

With ML factor analysis, you can test how many factors are required.

> Perhaps I could emulate this function by breaking it down 
> using factor extraction by principal component analysis and 
> the doing the varimax rotation second? If that makes any sense?
> 

Yes -- it shouldn't be hard to write your own PA factor-analysis function,
if that's what you prefer. For principal-components analysis, see ?princomp
and ?prcomp [which are turned up by help.search("principal components"), by
the way].

Regards,
 John