[R] having trouble extracting week from chron object

David Winsemius dwinsemius at comcast.net
Tue Aug 30 22:29:19 CEST 2011


You did read jannis' reply didn't you?

--  
David.
On Aug 30, 2011, at 2:34 PM, Christopher W Ryan wrote:

> Here it is with the output:
>
>> library(chron)
>> dts <- dates(c("02/27/92", "02/27/92", "01/14/92","02/28/92",  
>> "02/01/92"))
>> dts
> [1] 02/27/92 02/27/92 01/14/92 02/28/92 02/01/92
>> dts.chron <- as.chron(dts)
>> dts.chron
> [1] 02/27/92 02/27/92 01/14/92 02/28/92 02/01/92
>> class(dts.chron)
> [1] "dates" "times"
>> # all of these component extractions work:
>> months(dts.chron)
> [1] Feb Feb Jan Feb Feb
> 12 Levels: Jan < Feb < Mar < Apr < May < Jun < Jul < Aug < Sep < ...  
> < Dec
>> weekdays(dts.chron)
> [1] Thu Thu Tue Fri Sat
> Levels: Sun < Mon < Tue < Wed < Thu < Fri < Sat
>> years(dts.chron)
> [1] 1992 1992 1992 1992 1992
> Levels: 1992
>> quarters(dts.chron)
> [1] 1Q 1Q 1Q 1Q 1Q
> Levels: 1Q < 2Q < 3Q < 4Q
>> # but weeks() doesn't seem to work
>> weeks(dts.chron)
> Error: could not find function "weeks"
>> ?weeks
> No documentation for 'weeks' in specified packages and libraries:
> you could try '??weeks'
>> weeks
> Error: object 'weeks' not found
>> week
> Error: object 'week' not found
>>
>> sessionInfo()
> R version 2.13.1 (2011-07-08)
> Platform: i386-pc-mingw32/i386 (32-bit)
>
> locale:
> [1] LC_COLLATE=English_United States.1252
> [2] LC_CTYPE=English_United States.1252
> [3] LC_MONETARY=English_United States.1252
> [4] LC_NUMERIC=C
> [5] LC_TIME=English_United States.1252
>
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
>
> other attached packages:
> [1] chron_2.3-42
>
> Thanks.
>
> --Chris Ryan
>
>
> On Tue, Aug 30, 2011 at 1:54 PM, David Winsemius <dwinsemius at comcast.net 
> > wrote:
>>
>> On Aug 30, 2011, at 1:36 PM, Christopher W Ryan wrote:
>>
>>> Running R 2.13.1 on Windows XP.
>>> I would like to get week of the year (1-52) for each date.
>>>
>>> library(chron)
>>> dts <- dates(c("02/27/92", "02/27/92", "01/14/92","02/28/92",  
>>> "02/01/92"))
>>> dts
>>> dts.chron <- as.chron(dts)
>>> dts.chron
>>> class(dts.chron)
>>> # all of these component extractions work:
>>> months(dts.chron)
>>> weekdays(dts.chron)
>>> years(dts.chron)
>>> quarters(dts.chron)
>>> # but weeks() doesn't seem to work
>>
>> It doesn't "work" for me either but since I also have the package  
>> lubridate
>> loaded, and ?weeks brings up a lubridate help page, I don't feel I  
>> have any
>> right to complain. I get an error message.... what did you get?:
>>
>> Error in Ops.dates(pieces$week, 7) : * not defined for chron objects
>>
>> If I were posting I would also have had the good sense to include  
>> the output
>> of sessionInfo().
>>
>>> weeks(dts.chron)
>>
>> Try type just:
>>
>>  weeks  # I get a lubridate function.
>>
>>>
>>> ?chron tells me:
>>
>>
>> Bur what does ?weeks tell you?
>>
>>> . . . The functions days(), months(), quarters(),
>>> years(), weeks(), weekdays(), hours(), minutes(), and seconds() take
>>> any chron object as input and extract the corresponding time  
>>> interval
>>> . . . .
>>>
>>> Any advice?
>>>
>>> Thanks.
>>>
>>> Chris Ryan
>>> SUNY Upstate Medical University Clinical Campus at Binghamton
>>> Binghamton, NY
>>>
>>> ______________________________________________
>>> 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.
>>
>> David Winsemius, MD
>> West Hartford, CT
>>
>>
>
> ______________________________________________
> 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.

David Winsemius, MD
West Hartford, CT



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