[R] varimax rotation difference between R and SPSS

[Peter Dalgaard]

Andreas Cordes <andreas.cordes at stud.uni-goettingen.de> writes:

> 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.
> Maybe there is an obvious reason, but I somehow fail to see it.

I get 

> SPSS.res/ R.res
         V2        V3
1  2.315960 -1.461720
2  2.315960 -1.461720
3  2.315960 -1.461720
4  2.315960 -1.461720
5  2.315960 -1.461720
6  2.315960 -1.461719
7  2.315960 -1.461720
8  2.315960 -1.461720
9  2.315960 -1.461719
10 2.315960 -1.461720
11 2.315960 -1.461720
12 2.315960 -1.461720
13 2.315960 -1.461719
14 2.315960 -1.461720

which I presume is part of the puzzle. I don't think varimax() wants
its loadings normalized like they are in loadings(princomp())
(after all, it was designed for factanal(), not princomp()), and I
wouldn't be the least surprised if the $sdev components of princomp()
were related to  2.315960 and 1.461720.

-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
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