[R] min, median, mean on data frame (matrix)

Gabor Grothendieck ggrothendieck at gmail.com
Thu Dec 28 23:00:09 CET 2006


One can use sapply to get a consistent set of idioms despite the underlying
inconsistency of the functions themselves (using the builtin dataset anscombe):

sapply(anscombe, median)
sapply(anscombe, min)
sapply(anscombe, mean)

On 12/28/06, ivo welch <ivowel at gmail.com> wrote:
> dear r experts:
>
> I know its almost surely documented.  if d is a data frame
>
> median(d)  <-- fails (message is "need numeric data")
> min(d)  <-- succeeds, but gives a scalar.
> mean(d)  <-- gives a vector
>
> I am wondering whether this could be changed into something more
> consistent.  most naturally, the functions might just always return a
> vector.
>
> of course, if this change were made and if I wanted the old min() and
> max() behavior on a data frame, I would need to first flatten the
> data.
>
> just a thought...
>
> /iaw
>
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