factanal question

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
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