[R] factanal question

John Fox jfox at mcmaster.ca
Mon Dec 1 17:04:22 CET 2008


Dear Bill,

Thanks for pointing out that this functionality is already in the psych
package. Shouldn't factor.residuals() avoid this computation for oblique
rotations?

Regards,
 John

------------------------------
John Fox, Professor
Department of Sociology
McMaster University
Hamilton, Ontario, Canada
web: socserv.mcmaster.ca/jfox


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
On
> Behalf Of William Revelle
> Sent: December-01-08 10:26 AM
> To: John Fox; 'Don McNeil'
> Cc: r-help at r-project.org
> Subject: Re: [R] factanal question
> 
> Don and John,
>    factor.residuals in the psych package does what you want (and
> basically what  John wrote).
> 
> Bill
> 
> 
> At 9:30 AM -0500 12/1/08, John Fox wrote:
> >Dear Don,
> >
> >All long as you leave the factors unrotated or do an orthogonal rotation
(as
> >is the default), you can compute reproduced correlations among the
variables
> >from the factor loadings, and thus residual correlations given the
loadings
> >and the original correlation matrix, both of which are accessible in the
> >object returned by factanal(); the following isn't carefully tested, but
> >should work:
> >
> >repRes <- function(F, round=3){
> >   A <- loadings(F)
> >   R <- F$correlation
> >   RR <- A %*% t(A)
> >   ResR <- R - RR
> >   list(reproduced.correlations=round(RR, round),
> >     residual.correlations=round(ResR, round))
> >   }
> >
> >Here F is an object returned by factanal(). The diagonal elements of the
> >reproduced correlations are the communalities, and of the residual
> >correlations, the uniquenesses.
> >
> >To do this from an oblique rotation would require the factor-correlation
> >matrix, which, as has been pointed out previously, factanal() oddly
doesn't
> >provide. In this case, that's not a real impediment, since reproduced and
> >residual correlations are invariant with respect to rotation of the
factors.
> >
> >I hope this helps,
> >  John
> >
> >------------------------------
> >John Fox, Professor
> >Department of Sociology
> >McMaster University
> >Hamilton, Ontario, Canada
> >web: socserv.mcmaster.ca/jfox
> >
> >
> >>  -----Original Message-----
> >>  From: r-help-bounces at r-project.org
[mailto:r-help-bounces at r-project.org]
> >On
> >>  Behalf Of Don McNeil
> >>  Sent: November-30-08 11:39 PM
> >>  To: r-help at r-project.org
> >>  Subject: [R] factanal question
> >>
> >>  Dear R users:
> >>  I'm wondering if it's possible to get the residual correlation matrix
> when
> >>  using factanal.
> >>  Since factanal assumes that the errors are normally distributed and
> >>  independent (provided the factor model fits the data) this would be
> >useful.
> >>  Of course you would need to submit the data to the function to get the
> >>  residuals (not just their correlation matrix), but it should be
possible
> >to
> >>  get the residual correlation matrix if only the data correlation
matrix
> is
> >>  provided.
> >>  Don McNeil
> >>
> >>  ______________________________________________
> >>  R-help at r-project.org mailing list
> >>  https://stat.ethz.ch/mailman/listinfo/r-help
> >>  PLEASE do read the posting guide
> >http://www.R-project.org/posting-guide.html
> >>  and provide commented, minimal, self-contained, reproducible code.
> >
> >______________________________________________
> >R-help at r-project.org mailing list
> >https://stat.ethz.ch/mailman/listinfo/r-help
> >PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> >and provide commented, minimal, self-contained, reproducible code.
> 
> 
> --
> William Revelle		http://personality-project.org/revelle.html
> Professor
http://personality-project.org/personality.html
> Department of Psychology
http://www.wcas.northwestern.edu/psych/
> Northwestern University	http://www.northwestern.edu/
> Attend  ISSID/ARP:2009               http://issid.org/issid.2009/
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.



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