Re: [Rd] random output with sub(fixed = TRUE)

From: Duncan Murdoch <murdoch_at_stats.uwo.ca>
Date: Thu 22 Dec 2005 - 04:24:05 GMT

On 12/21/2005 5:13 PM, Roger D. Peng wrote:

> Well, who am I to break this long-standing ritual? :)
> 
> Interestingly, while the printed output looks wrong, I get
> 
>  > v <- paste(0:10, "asdf", sep = ".")
>  > a <- sub(".asdf", "", v, fixed = TRUE)
>  > b <- as.character(0:10)
>  > identical(a, b)
> [1] TRUE
>  >
> 
> -roger

I think finding two separate bugs on the day after the release goes a bit beyond what is necessary to satisfy the ritual.

Duncan Murdoch

> 
> Peter Dalgaard wrote:
> 

>>"Roger D. Peng" <rpeng@jhsph.edu> writes:
>>
>>
>>
>>>I've noticed what I think is curious behavior in using 'sub(fixed = TRUE)' and
>>>was wondering if my expectation is incorrect. Here is one example:
>>>
>>>v <- paste(0:10, "asdf", sep = ".")
>>>sub(".asdf", "", v, fixed = TRUE)
>>>
>>>The results I get are
>>>
>>>
>>>>sub(".asdf", "", v, fixed = TRUE)
>>>
>>> [1] "0" "1\0st\0\0" "2\0<af>\001\0\0" "3\0<af>\001\0\0"
>>> [5] "4\0mes\0" "5\0<ba>\001\0\0" "6\0\0\0\0\0" "7\0\0\0m\0"
>>> [9] "8\0\0\0t\0" "9\0<fe>\0\0\0" "10\0\0\0\0\0"
>>>
>>>I expected "0" in the first entry and everything else would be unchanged. Your
>>>results may vary since every time I run 'sub()' in this way, I get a slightly
>>>different answer in entires 2 through 11.
>>>
>>>As it turns out, 'gsub(fixed = TRUE)' gives me the answer I *actually* wanted,
>>>which was to replace the string in every entry. But I still think the behavior
>>>of 'sub(fixed = TRUE) is a bit odd.
>>>
>>>
>>>>version
>>>
>>> _
>>>platform x86_64-unknown-linux-gnu
>>>arch x86_64
>>>os linux-gnu
>>>system x86_64, linux-gnu
>>>status
>>>major 2
>>>minor 2.1
>>>year 2005
>>>month 12
>>>day 20
>>>svn rev 36812
>>>language R
>>>
>>
>>Argh...
>>
>>year 2005
>>month 12
>>day 21
>>
>>and something like this gets discovered. It's a ritual, I tell ya, a ritual!
>>
>>If you look at the output and terminate all strings at the embedded
>>\0, it looks much more sensible, so it should be fairly easy to spot
>>the cause of this bug...
>>
>
>

R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel Received on Thu Dec 22 15:29:47 2005

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