[Rd] R string comparisons may vary with platform (plain text)

Henrik Bengtsson hb at biostat.ucsf.edu
Sun Nov 23 01:05:33 CET 2014


On Sat, Nov 22, 2014 at 12:42 PM, Duncan Murdoch
<murdoch.duncan at gmail.com> wrote:
> On 22/11/2014, 2:59 PM, Stuart Ambler wrote:
>> A colleague¹s R program behaved differently when I ran it, and we thought
>> we traced it probably to different results from string comparisons as
>> below, with different R versions.  However the platforms also differed.  A
>> friend ran it on a few machines and found that the comparison behavior
>> didn¹t correlate with R version, but rather with platform.
>>
>> I wonder if you¹ve seen this.  If it¹s not some setting I¹m unaware of,
>> maybe someone should look into it.  Sorry I haven¹t taken the time to read
>> the source code myself.
>
> Looks like a collation order issue.  See ?Comparison.

With the oddity that both platforms use what look like similar locales:

LC_COLLATE=en_US.UTF-8
LC_COLLATE=en_US.utf8

/Henrik

>
> Duncan Murdoch
>
>> Thanks,
>> Stuart
>>
>> R version 3.0.2 (2013-09-25) -- "Frisbee Sailing"
>> Platform: x86_64-unknown-linux-gnu (64-bit)
>> 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=en_US.UTF-8;LC_
>> NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_US.UTF-8;LC_IDENTIFICA
>> TION=C"
>>
>> "-1" > "1"
>> [1] TRUE
>>
>> "-1" <"1"
>> [1] FALSE
>>
>> "1" < "-1"
>> [1] TRUE
>>
>> "1" < "-"
>> [1] FALSE
>>
>> Vs.
>>
>> R version 3.1.1 (2014-07-10) ‹ ³Sock it to Me"
>> Platform: x86_64-redhat-linux-gnu (64-bit)
>> Sys.getlocale()
>> [1]
>> "LC_CTYPE=en_US.utf8;LC_NUMERIC=C;LC_TIME=en_US.utf8;LC_COLLATE=en_US.utf8
>> ;LC_MONETARY=en_US.utf8;LC_MESSAGES=en_US.utf8;LC_PAPER=en_US.utf8;LC_NAME
>> =C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_US.utf8;LC_IDENTIFICATION
>> =C"
>>
>> "-1" > "1"
>> [1] FALSE
>>
>> "-1" <"1"
>> [1] TRUE
>>
>> "1" < "-1"
>> [1] FALSE
>>
>> "1" < "-"
>> [1] FALSE
>>
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>>
>
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