Message-ID: <Pine.LNX.4.61.0505051625410.10592@gannet.stats>
Date: 2005-05-05T15:28:40Z
From: Brian Ripley
Subject: body of non-visible function
In-Reply-To: <427A30B8.70705@niss.org>
getS3method("princomp", "default").
getAnywhere("princomp.default")
The first of these is in the See Also of ?methods.
On Thu, 5 May 2005, Anna Oganyan wrote:
> 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) doesnt show it.
>
> In particular, I guess I have a very na?ve question&
> Id 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.
You have forgotten to centre your data. It may be more helpful to look at
the predict method.
--
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595