On 20.12.2010 06:54, Luca Meyer wrote:
All right, I get it now: lubridate's week() define weeks from Thursday till the
following Wednesday. You'd probably agree with me that it's a bit strange what
it is going to do over the turn of the year:
y<-
as.POSIXct(c("2010-12-27","2010-12-28","2010-12-29","2010-12-30","2010-12-31","2011-01-01","2011-01-02","2011-01-03","2011-01-04","2011-01-05","2011-01-06","2011-01-07","2011-01-08","2011-01-09","2011-01-10","2011-01-11","2010-01-12","2010-01-13","2010-01-14"))
week(y)
[1] 52 52 52 53 53 1 1 1 1 1 1 2 2 2 2 2 2 2 3
Why would the first week of the year be made of 6 days and the turn from week 1
to week 2 on the night between Thursday and Friday and not Wednesday and Friday
like every other week?
Well, it's the definition in that week() function from that package, if
you don't like that definition, choose another one. I have not said that
I like it, just that it seems to work as documented.
Uwe
Cheers,
Luca
Il giorno 19/dic/2010, alle ore 18.14, Uwe Ligges ha scritto:
On 19.12.2010 13:20, David Winsemius wrote:
On Dec 19, 2010, at 5:11 AM, Luca Meyer wrote:
Something goes wrong with the week function of the lubridate package:
x= as.POSIXct(factor(c("2010-12-15 17:28:27",
+ "2010-12-15 17:32:34",
+ "2010-12-15 18:48:39",
+ "2010-12-15 19:25:00",
+ "2010-12-16 08:00:00",
+ "2010-12-16 08:25:49",
+ "2010-12-16 09:00:00")))
require(lubridate)
weekdays(x)
[1] "Mercoledì" "Mercoledì" "Mercoledì" "Mercoledì" "Giovedì"
"Giovedì" "Giovedì"
week(x)
[1] 50 50 50 50 51 51 51
But 2010-12-15 is a Wednesday and 2010-12-16 is a Thursday.
Together with the description of ?week this shows that lubridate's week()
function works as documented rather than as expected by Luca Meyer.
Uwe Ligges
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