Hi Bill and Josh:

When I run any "principal" code with scores=TRUE, I get the following  
Error:

Error in principal (my.data,3,scores=TRUE) : unused argument  
(scores=TRUE)

Thoughts?

Thanks,
Shari






On 3-Mar-11, at 9:42 PM, William Revelle wrote:

> Shari,
>  Josh partly answered your question, but his example did not include  
> rotation because he took out just one factor.
>
> Try:
>
> require(psych)
> mt.pc <- principal(mtcars,3,scores=TRUE)   #this gives you the  
> varimax rotated first 3 principal components
> #pc.scores <- mt.pc$scores     #here are the scores
>
> biplot(mt.pc)    #show the data as well as the principal components  
> in a biplot
>
>
>
> Bill
>
>
> At 5:15 PM -0800 3/3/11, Joshua Wiley wrote:
>> Hi Shari,
>>
>> Yes, please look at the documentation for principal.  You can access
>> this (assuming you have loaded psych) by typing at the console:
>>
>> ?principal
>>
>> note the logical argument "scores".
>>
>> Here is a small example:
>>
>> ##############################
>> require(psych)
>> require(GPArotation)
>>
>> dat <- principal(mtcars[, c("mpg", "hp", "wt")], nfactors = 1,
>>  rotate = "oblimin", scores = TRUE)
>>
>> dat$scores
>> ##############################
>>
>> Cheerio,
>>
>> Josh
>>
>> On Thu, Mar 3, 2011 at 1:02 PM, Shari Clare <sclare@ualberta.ca>  
>> wrote:
>>> I am running a PCA, but would like to rotate my data and limit the
>>> number of factors that are analyzed.  I can do this using the
>>> "principal" command from the psych package [principal(my.data,
>>> nfactors=3,rotate="varimax")], but the issue is that this does not
>>> report scores for the Principal Components the way "princomp" does.
>>>
>>> My question is:
>>>
>>> Can you get an output of scores using "principal" OR, is there a way
>>> to limit the number of factors that are included when you use
>>> "princomp"?
>>>
>>> Thanks,
>>> Shari Clare
>>>
>>> PhD Candidate
>>> Department of Renewable Resources
>>> University of Alberta
>>> sclare@ualberta.ca
>>> 780-492-2540
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>        [[alternative HTML version deleted]]
>>>
>>> ______________________________________________
>>> 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
>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>
>>
>>
>> --
>> Joshua Wiley
>> Ph.D. Student, Health Psychology
>> University of California, Los Angeles
>> http://www.joshuawiley.com/
>>
>> ______________________________________________
>> 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
>> and provide commented, minimal, self-contained, reproducible code.
>


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