[R] factor analysis

[Andrew Criswell]

Hello:

The website 
http://ourworld.compuserve.com/homepages/jsuebersax/tetra.htm might 
provide you with further hints and information on implementing 
polychoric correlations. Further information related to your inquiry can 
also be found on http://www.unt.edu/rss/class/rich/5840/

In addition, possibly relevant S+ code can be found on 
http://www.biostat.wustl.edu/archives/html/s-news/2001-02/msg00079.html

ANDREW

John Fox wrote:

>Dear Allan,
>
>I assume that the categorical data are ordinal. There are methods for
>factor analyzing ordinal data (e.g., using polychoric correlations) and
>mixed ordinal and interval data, but as far as I know, these aren't
>implemented in R.
>
>John
>
>On Thu, 13 May 2004 18:32:11 +0200
> allan clark <allan at stats.uct.ac.za> wrote:
>  
>
>>hi all
>>
>>this is a stats question.
>>
>>when undertaking factor analysis should the variables included always
>>be
>>continiuos random variables? could one include categorical data? e.g
>>some survey type data
>>
>>my gut feeling is that one should not include categorical type data
>>since factor analysis is based on the eigenanalysis of the
>>correlation
>>matrix of a group of variables. The introduction of categorical data
>>into a data set might "mess up" the corelation matrix.
>>
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>>    
>>
>
>
>--------------------------------
>John Fox
>Department of Sociology
>McMaster University
>Hamilton, Ontario, Canada
>http://socserv.mcmaster.ca/jfox/
>
>______________________________________________
>R-help at stat.math.ethz.ch mailing list
>https://www.stat.math.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
>
>
>
>  
>