[Rd] ?mean
Martin Maechler
maechler at stat.math.ethz.ch
Thu Jan 25 17:48:32 CET 2007
>>>>> "Gabor" == Gabor Grothendieck <ggrothendieck at gmail.com>
>>>>> on Thu, 25 Jan 2007 09:53:49 -0500 writes:
Gabor> The help page for mean does not say what happens when one
Gabor> applies mean to a matrix.
Gabor> mean and sd work in an inconsistent way on a matrix
Gabor> so that should at least be documented.
You are right (though I think this *was* documented at some
point in time).
As a matter of fact, I hate the the inconsistencies you've
been mentioning, and I think is very wrong from an S-pedagogical
point of view.... both
that sd(mat) :<==> apply(mat, 2, sd)
and mean(dfr) :<==> apply(dfr, 2, mean)
and it leads just to wrong ``analogy conclusions'' by useRs.
I'd vote for deprecating these ``builtin conveniences''
in order to gain consistency and clarity...
Though I haven't checked how many CRAN + Bioconductor packages
would break if we'd disactivate these two mis-features ...
Martin
Gabor> Also there should be a See Also to colMeans since that
Gabor> provides the missing column-wise analog to sd.
More information about the R-devel
mailing list