Re: [Rd] ?mean

From: Martin Maechler <>
Date: Thu 25 Jan 2007 - 16:48:32 GMT

>>>>> "Gabor" == Gabor Grothendieck <>
>>>>> 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 ...


    Gabor> Also there should be a See Also to colMeans since that     Gabor> provides the missing column-wise analog to sd. mailing list Received on Fri Jan 26 03:54:23 2007

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