[R] having trouble extracting week from chron object

[Jannis]

Well, there is no function called "weeks" in chron. Funny that the help mentions it.


You can, however, use normal POSIXct objects and extract the week with:

 dts <- dates(c("02/27/92", "02/27/92"))
 dts.posx <- as.POSIXct(dts)
 result   <- as.integer(format(dts.posx,format="%W"))



HTH
Jannis

--- Christopher W Ryan <cryan at binghamton.edu> schrieb am Di, 30.8.2011:

> Von: Christopher W Ryan <cryan at binghamton.edu>
> Betreff: [R] having trouble extracting week from chron object
> An: R-help at r-project.org
> Datum: Dienstag, 30. August, 2011 17:36 Uhr
> 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
> weeks(dts.chron)
> 
> ?chron tells me: . . . 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
> 
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