Jean-Luc,
Please keep the communications on the list, for the benefit of others, now and
in the future, via the list archive. I am adding r-devel back here.
I can't speak to the rationale in some of these cases. As I noted, it may be
(is likely) due to differing authors over time, and there may have been
relevant use cases at the time that the code was written, resulting in the
various checks. Presumably, the additional checks were not incorporated into
the other functions to enforce a level of consistency.
We will need to wait for someone from R Core to comment.
Regards,
Marc
> On Jan 9, 2020, at 8:34 AM, Lipatz Jean-Luc <jean-luc.lip...@insee.fr> wrote:
>
> Ok, inconstencies.
>
> The last test you wrote is a bit strange. I agree that it is useful to warn
> about a computation that have no sense in the case of factors. But why
> testing data;frames? If you go that way using random structures, you can also
> try :
>
>> median(list(1,2),list(3,4),list(4,5))
> Error in if (na.rm) x <- x[!is.na(x)] else if (any(is.na(x)))
> return(x[FALSE][NA]) :
> l'argument n'est pas interprétable comme une valeur logique
> De plus : Warning message:
> In if (na.rm) x <- x[!is.na(x)] else if (any(is.na(x))) return(x[FALSE][NA]) :
> la condition a une longueur > 1 et seul le premier élément est utilisé
>
> giving a message which, despite of his length, doesn't really explain the
> reason of the error.
>
> Why not a test on arguments like?
> if (!is.numeric(x))
> stop("need numeric data")
>
>
> -----Message d'origine-----
> De : Marc Schwartz <marc_schwa...@me.com>
> Envoyé : jeudi 9 janvier 2020 14:19
> À : Lipatz Jean-Luc <jean-luc.lip...@insee.fr>
> Cc : R-Devel <r-devel@r-project.org>
> Objet : Re: [Rd] mean
>
>
>> On Jan 9, 2020, at 7:40 AM, Lipatz Jean-Luc <jean-luc.lip...@insee.fr> wrote:
>>
>> Hello,
>>
>> Is there a reason for the following behaviour?
>>> mean(c("1","2","3"))
>> [1] NA
>> Warning message:
>> In mean.default(c("1", "2", "3")) :
>> l'argument n'est ni numérique, ni logique : renvoi de NA
>>
>> But:
>>> var(c("1","2","3"))
>> [1] 1
>>
>> And also:
>>> median(c("1","2","3"))
>> [1] "2"
>>
>> But:
>>> quantile(c("1","2","3"),p=.5)
>> Error in (1 - h) * qs[i] :
>> argument non numérique pour un opérateur binaire
>>
>> It sounds like a lack of symetry.
>> Best regards.
>>
>>
>> Jean-Luc LIPATZ
>> Insee - Direction générale
>> Responsable de la coordination sur le développement de R et la mise en
>> oeuvre d'alternatives à SAS
>
>
> Hi,
>
> It would appear, whether by design or just inconsistent implementations,
> perhaps by different authors over time, that the checks for whether or not
> the input vector is numeric differ across the functions.
>
> A further inconsistency is for median(), where:
>
>> median(c("1", "2", "3", "4"))
> [1] NA
> Warning message:
> In mean.default(sort(x, partial = half + 0L:1L)[half + 0L:1L]) :
> argument is not numeric or logical: returning NA
>
> as a result of there being 4 elements, rather than 3, and the internal checks
> in the code, where in the case of the input vector having an even number of
> elements, mean() is used:
>
> if (n%%2L == 1L)
> sort(x, partial = half)[half]
> else mean(sort(x, partial = half + 0L:1L)[half + 0L:1L])
>
>
> Similarly:
>
>> median(factor(c("1", "2", "3")))
> Error in median.default(factor(c("1", "2", "3"))) : need numeric data
>
> because the input vector is a factor, rather than character, and the initial
> check has:
>
> if (is.factor(x) || is.data.frame(x))
> stop("need numeric data")
>
>
> Regards,
>
> Marc Schwartz
>
>
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
