[R] varimax rotation difference between R and SPSS

[Jari Oksanen]

On Thu, 2005-10-13 at 16:13 +0200, Andreas Cordes wrote:
> Hi,
> I am puzzeled with a differing result of princomp in R and FACTOR in 
> SPSS. Regarding the amount of explained Variance, the two results are 
> the same. However, the loadings differ substantially, in the unrotated 
> as well as in the rotated form.
> In both cases correlation matrices are analyzed. The sums of the squared 
> components is one in both programs.

Not in the data that you pasted in your message. After reading in the
data I get from the non-rotated R solution:

> colSums(rpc^2)
V2 V3
 1  1

And the non-rotated SPSS solutions gives:

> colSums(spc^2)
      V2       V3
5.363671 2.136624

After normalizing the SPSS pc's, the solutions are identical (within
numerical accuracy) after reversing the sign of second pc.

I don't want to look at the data full of holes, like the loadings from
varimax rotation. However, it seems that the raw solutions are
identical.

cheers, jari oksanen

-- 
Jari Oksanen -- Dept Biology, Univ Oulu, 90014 Oulu, Finland