[Rd] Why is strptime always returning a vector of length 9 ?

[Jeff Ryan]

The reason is in the ?strptime under value:

'strptime' turns character representations into an object of class
     '"POSIXlt"'.  The timezone is used to set the 'isdst' component
     and to set the '"tzone"' attribute if 'tz != ""'.

And POSIXlt is a list of length 9.


HTH
Jeff

On Sun, Aug 9, 2009 at 10:35 AM, Gabor
Grothendieck<ggrothendieck at gmail.com> wrote:
> 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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>>
>
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-- 
Jeffrey Ryan
jeffrey.ryan at insightalgo.com

ia: insight algorithmics
www.insightalgo.com