Thank you very much Bill!!!  We get it. The results are the same.

Best wishes,

Alberto



2009/1/30 William Revelle <lists@revelle.net>

> At 3:00 PM +0100 1/30/09, Alberto Maceda Veiga wrote:
>
>> Hi!
>>
>> I am trying to analyse with R a database that I have previously analysed
>> with SPSS.
>>
>> Steps with SPSS:
>>
>> Factorial analysis
>>  Extraction options : I select = Principal component analysis
>>  Rotation: varimax
>>
>
> Unfortunately, SPSS labels principal components as a factor model. It is
> not.   So, extracting the first n factors by using factanal will give you a
> very different solution than the first n principal components.
>
>
>
>> Steps with R:
>>
>> I have tried it with varimax function with factanal or with princomp...and
>> the results are different of what I have with SPSS. I think that varimax
>> function is incorporated in factanal function.
>>
>>
>> Does anybody know which are the instructions into R to do exactly the same
>> of what I have done with SPSS???
>>
>
> To duplicate the SPSS analysis try using the psych package.
>
> The principal function in the psych package will extract the first n
> components (defaults to 1) and then by default rotate using varimax.
>
> library(psych)
> pc <- principal(my.data,n)  #where n is the number components you want to
> extract
>
> Let me know if this matches the SPSS output.
>
> Bill
>
>
>
>
>
>
>
>>
>>
>> Thank you very much!
>>
>>        [[alternative HTML version deleted]]
>>
>> ______________________________________________
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>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html<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@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<http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Alberto Maceda Veiga
Departamento de Biología Animal
Vertebrados. 1ª Planta. Despacho 151.
Facultad de Biología
Universidad de Barcelona
Av. Diagonal, 645
08028 Barcelona
Spain
Tel: 93 4021041
Fax: 93 4034426
Email: albertomaceda@gmail.com
><((((º>  ><((((º>  ><((((º>

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