[R] apply and factor

[Laurent Gautier]

Prof Brian D Ripley wrote:
> 
> On Fri, 10 Aug 2001, Rachel Cunliffe wrote:
> 
> > Hi again
> >
> > Why does this occur?
> >
> > > test <- apply(data,2,factor)  # where data is a data.frame
> > > is.factor(test[,1])
> > [1] FALSE
> 
> test is a *matrix*, see ?apply.  No factors in matrices! 
> Using `data' as a name is probably a bad idea in R: it's an important
> function name.


As R extends, the number of important function names is likely to keep
growing.
(And I have seen Pr. Ripley mentionning more than once that one was
overriding an important funcion).
A good mannered user should check the existance of a function before
choosing to giving a name... that may be not what is done...
I was thinking of a switch to warn the user of function overriding (the
switch could be somewhere in the options() ). The disavantage of such a
thing might be a slowdown of the execution R scripts, and most likely
may require a lot of implementation efforts, to set this in the existing
code, for a rather minor improvement. An another, and may be less
general, mecanism would be to have a special status for the functions of
R-base. Their overriding would require an explicit statement...

...Does this that make any sense ?






Regards,





Laurent




-- 
Laurent Gautier			CBS, Building 208, DTU
PhD. Student			D-2800 Lyngby,Denmark	
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