RE: [R] body of non-visible function

From: Liaw, Andy <andy_liaw_at_merck.com>
Date: Fri 06 May 2005 - 01:24:02 EST


> From: Anna Oganyan
>
> Hello,
> Is there any possibility in R to see the body of the "non-visible"
> function, for
> example "princomp"?
> If I do :
>
> > methods(princomp)
>
> so, I get that princomp.default and princomp.formula are non-visible
> functions and
> body(princomp.default) doesn't show it.

You may want to learn about getAnywhere() and getS3method().  

> In particular, I guess I have a very na´ve question...
> I'd like to see how scores calculation is implemented in the function
> princomp. Because when I multiply my data matrix on the
> matrix of loadings
> >data.matrix %*% princomp(data.matrix, scores=T)$loadings
>
> I get different result than just doing
>
> >princomp(data.matrix, scores=T)$scores.

Variables are centered and scaled, so you want to do

  scale(data.matrix) %*% loadings(princomp(data.matrix))

Andy  

> Thanks.
> Anna
>
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>



R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Fri May 06 01:41:38 2005

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