[R] min(NA,"bla") != min("bla", NA)

[Ista Zahn]

On Thu, Sep 26, 2013 at 9:10 PM, Rolf Turner <rolf.turner at xtra.co.nz> wrote:
> On 09/27/13 11:07, Duncan Murdoch wrote:
>>
>> On 13-09-26 5:32 PM, Rolf Turner wrote:
>>>
>>>
>>> Just to add to the confusion, on my system I get NA --- which I
>>> understand to be
>>> the correct value --- from all of min(NA,"bla"), min("bla",NA),
>>> min(c(NA,"bla")), and
>>> min(c("bla",NA)).  When I append the argument na.rm=TRUE to each of the
>>> calls,
>>> I get "bla" from each.
>>>
>>> So, no bug in my system.
>>
>>
>> I've just built a 3.0.1 version, and I definitely see the bug there. What
>> do you get from these expressions?
>>
>> str(min(NA, "bla"))
>> str(min("bla", NA))
>> str(min(NA_character_, "bla"))
>>
>> I get
>>
>> > str(min(NA, "bla"))
>>  int NA
>> > str(min("bla", NA))
>>  chr "bla"
>> > str(min(NA_character_, "bla"))
>>  chr "bla"
>>
>> on both Windows and OSX R 3.0.1.  After today's patch, I get
>>
>>  chr NA
>>
>> for all three.
>
>
> I get:
>
>> str(min(NA, "bla"))
>  int NA
>  > str(min("bla", NA))
>  chr NA
>> str(min(NA_character_, "bla"))
>  chr NA
>
> Which looks to me to be as it should be.  How come my system's so good
> compared to others? :-)

It's not; you just have your locale set differently;

> Sys.getlocale()
[1] "LC_CTYPE=en_US.UTF-8;LC_NUMERIC=C;LC_TIME=en_US.UTF-8;LC_COLLATE=en_US.UTF-8;LC_MONETARY=en_US.UTF-8;LC_MESSAGES=en_US.UTF-8;LC_PAPER=C;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_US.UTF-8;LC_IDENTIFICATION=C"
> for(l in letters) print(min(l, NA))
[1] "a"
[1] "b"
[1] "c"
[1] "d"
[1] "e"
[1] "f"
[1] "g"
[1] "h"
[1] "i"
[1] "j"
[1] "k"
[1] "l"
[1] "m"
[1] "n"
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
> Sys.setlocale("LC_ALL", "C")
[1] "LC_CTYPE=C;LC_NUMERIC=C;LC_TIME=C;LC_COLLATE=C;LC_MONETARY=C;LC_MESSAGES=en_US.UTF-8;LC_PAPER=C;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_US.UTF-8;LC_IDENTIFICATION=C"
> for(l in letters) print(min(l, NA))
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
[1] NA
> sessionInfo()
R version 3.0.1 (2013-05-16)
Platform: x86_64-unknown-linux-gnu (64-bit)

locale:
 [1] LC_CTYPE=C                 LC_NUMERIC=C
 [3] LC_TIME=C                  LC_COLLATE=C
 [5] LC_MONETARY=C              LC_MESSAGES=en_US.UTF-8
 [7] LC_PAPER=C                 LC_NAME=C
 [9] LC_ADDRESS=C               LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

Best,
Ista

>
>     cheers,
>
>     Rolf
>
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.