[R] factanal question

[William Revelle]

At 11:04 AM -0500 12/1/08, John Fox wrote:
>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?

John,
Good suggestion.  I will add that in the next revision.

Bill


>
>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.


-- 
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/