[R] sprucing up the R homepage

Peter Dalgaard p.dalgaard at biostat.ku.dk
Sat Sep 29 15:08:16 CEST 2007


Antony Unwin wrote:
>
> On 27 Sep 2007, at 5:11 pm, Peter Dalgaard wrote:
>
>> There was a competition in 2004, and this is the display that won.
>
> Thanks for clearing that up.
>
>> It was deliberately designed as a "show-off" for the home page, and as
>> such, I don't think it can be the same sort of graphic that you'd use
>> for real analysis. It does have the nice feature of displaying results
>> of simple, yet non-trivial statistical analyses (PCA, clustering)
>> without requiring a lengthy explanation.
>
> Do you really think of PCA and clustering as "statistical" analyses? 
> And anyway, surely it's a factor analysis not PCA?  Perhaps lengthy 
> explanations are needed after all.  I would need an explanation for 
> the curious plots lower right.  It's probably due to my sheltered 
> upbringing, as I was always taught to keep factor analyses at a 
> respectable distance.
>
> I liked Hadley's comment.  It struck me as fortun(at)e.
>
Hmm, well, ... Actually it _is_ PCA (it says so: princomp), but it quite 
possibly ought to have been a factor analysis. The former is often used 
as a substitute for the latter (after rescaling) -- SPSS does this, 
causing a good deal of confusion to users expecting factanal () to have 
an option for PCA -- but that's not exactly a good reason to perpetuate it.

Whether it counts as statistical analysis? I tend to think that it does, 
although it isn't among the tools that I reach for most frequently.

-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907



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