R devel - Aug 2009 - Why is strptime always returning a vector of length 9 ?

Dear List,


I am having an issue with strptime (see below).
I can reproduce it on R-2.8, R-2.9, and R-2.10-dev, I tempted to see
either a bug or my misunderstanding (and then I just don't currently see
where).

# setup:
x <- c("March 09, 2007", "May 31, 2007", "November
12, 2008", "November
12, 2008", "July 30, 2009", "July 30, 2009" )

# showing the problem
> length(x)
6
> xd <- strptime(x, format = "%B %d, %Y")
> length(xd)
9
> xd[1:9]
[1] "2007-03-09" "2007-05-31" "2008-11-12"
"2008-11-12" "2009-07-30"
[6] "2009-07-30" NA           NA           NA  
> length(strptime(rep(x, 2), format="%B %d, %Y"))
[1] 9
> strptime(rep(x, 2), format="%B %d, %Y")[1:12]
 [1] "2007-03-09" "2007-05-31" "2008-11-12"
"2008-11-12" "2009-07-30"
 [6] "2009-07-30" "2007-03-09" "2007-05-31"
"2008-11-12" "2008-11-12"
[11] "2009-07-30" "2009-07-30

Any pointer would be appreciated.



L.

Try this to see its components:
> str(unclass(xd))
List of 9
 $ sec  : num [1:6] 0 0 0 0 0 0
 $ min  : int [1:6] 0 0 0 0 0 0
 $ hour : int [1:6] 0 0 0 0 0 0
 $ mday : int [1:6] 9 31 12 12 30 30
 $ mon  : int [1:6] 2 4 10 10 6 6
 $ year : int [1:6] 107 107 108 108 109 109
 $ wday : int [1:6] 5 4 3 3 4 4
 $ yday : int [1:6] 67 150 316 316 210 210
 $ isdst: int [1:6] 0 1 0 0 1 1

and read R News 4/1 for more.

On Sun, Aug 9, 2009 at 10:20 AM, laurent<lgautier at gmail.com>
wrote:
> Dear List,
>
>
> I am having an issue with strptime (see below).
> I can reproduce it on R-2.8, R-2.9, and R-2.10-dev, I tempted to see
> either a bug or my misunderstanding (and then I just don't currently
see
> where).
>
> # setup:
> x <- c("March 09, 2007", "May 31, 2007",
"November 12, 2008", "November
> 12, 2008", "July 30, 2009", "July 30, 2009" )
>
> # showing the problem
>> length(x)
> 6
>> xd <- strptime(x, format = "%B %d, %Y")
>> length(xd)
> 9
>> xd[1:9]
> [1] "2007-03-09" "2007-05-31" "2008-11-12"
"2008-11-12" "2009-07-30"
> [6] "2009-07-30" NA ? ? ? ? ? NA ? ? ? ? ? NA
>> length(strptime(rep(x, 2), format="%B %d, %Y"))
> [1] 9
>> strptime(rep(x, 2), format="%B %d, %Y")[1:12]
> ?[1] "2007-03-09" "2007-05-31" "2008-11-12"
"2008-11-12" "2009-07-30"
> ?[6] "2009-07-30" "2007-03-09" "2007-05-31"
"2008-11-12" "2008-11-12"
> [11] "2009-07-30" "2009-07-30
>
> Any pointer would be appreciated.
>
>
>
> L.
>
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