R help - Sep 2004 - R conversion

I am a newcomer to R trying to convert a SAS program to R.
Does anyone know if there is a functional equivalent of the SAS 
'Factor' procedure?

For example in SAS:

proc factor DATA=cor method=principal rotate=varimax proportion=0.9 scree

where 'cor' is a correlation matrix (as in the R 'cor' function)

This should get you a list of eigen values as well as a factor
pattern matrix.

Also why when I use the 'eigen' function in R does it seem to give
a subtly different answer to the eigen values generated by the above
program?

Many thanks for any help

Mark Strivens
-----------------------
Dept. Molecular and Human Genetics
Baylor College of Medicine
Houston, USA
strivens@bcm.edu
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Dear Mark,

See ?factanal for a factor-analysis function, in the standard stats package
(though factanal does ML factor analysis and not principal axes). Note that
help.search("factor analysis") turns this up.

With respect to your last question, it's not possible to know the source of
the difference without knowing what the difference is. A guess is that
specifying proportion=0.9 in SAS causes the program to use communality
estimates rather than 1's on the diagonal of the correlation matrix.

I hope this helps,
 John
> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Mark Strivens
> Sent: Thursday, September 09, 2004 7:26 PM
> To: r-help at stat.math.ethz.ch
> Subject: [R] R conversion
> 
> I am a newcomer to R trying to convert a SAS program to R.
> Does anyone know if there is a functional equivalent of the 
> SAS 'Factor' procedure?
> 
> For example in SAS:
> 
> proc factor DATA=cor method=principal rotate=varimax 
> proportion=0.9 scree
> 
> where 'cor' is a correlation matrix (as in the R 'cor'
function)
> 
> This should get you a list of eigen values as well as a 
> factor pattern matrix.
> 
> Also why when I use the 'eigen' function in R does it seem to 
> give a subtly different answer to the eigen values generated 
> by the above program?
> 
> Many thanks for any help
> 
> Mark Strivens