>>>>> Suharto Anggono Suharto Anggono via R-devel <r-devel@r-project.org>
>>>>> on Mon, 30 May 2016 17:20:08 +0000 writes:
> In R 3.3.0 (also in R 2.7.2), the documentation on 'factor', in "Details"
section, has this statement.
> 'factor(x, exclude = NULL)' applied to a factor is a no-operation unless
there are unused levels: in that case, a factor with the reduced level set is
returned.
> It is not true for a factor 'x' that has NA. In that case, if levels of
'x' doesn't contain NA, factor(x, exclude = NULL) adds NA as a level.
> If levels of a factor 'x' doesn't contain NA, factor(x) is a no-operation
if all levels are used.
So we should fix the documentation (only!), right ?
-------- -------
> In R 3.3.0 (also in R 3.1.3), for a named integer 'x', factor(x) has
names and as.factor(x) doesn't. It would be better if the behavior on names
were matched.
I agree .. for consistency with the named "double" case (and
also consistency with earlier versions of R) :
This is a bug indeed, only present in R versions >= 3.1.0
Another MRE is (note that '0' is "double"):
> as.factor(ni <- c(one = 1L, two = 2L)); factor(ni); as.factor(0+ni);
> factor(0+ni)
[1] 1 2
Levels: 1 2
one two
1 2
Levels: 1 2
one two
1 2
Levels: 1 2
one two
1 2
Levels: 1 2
>
>> x <- integer(1)
>> names(x) <- "a"
>> names(factor(x))
> [1] "a"
>> names(as.factor(x))
> NULL
>> sessionInfo()
> R version 3.3.0 (2016-05-03)
> Platform: i386-w64-mingw32/i386 (32-bit)
> Running under: Windows XP (build 2600) Service Pack 2
> locale:
> [1] LC_COLLATE=English_United States.1252
> [2] LC_CTYPE=English_United States.1252
> [3] LC_MONETARY=English_United States.1252
> [4] LC_NUMERIC=C
> [5] LC_TIME=English_United States.1252
> attached base packages:
> [1] stats graphics grDevices utils datasets methods base
> loaded via a namespace (and not attached):
> [1] tools_3.3.0
> ______________________________________________
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
