[R] Match ISO 8601 week-of-year numbers to month-of-year numbers on Windows with German locale

Thu Jan 12 22:20:42 CET 2017

See comments inline.

> -----Original Message-----
> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Bob Rudis
> Sent: Thursday, January 12, 2017 12:41 PM
> To: David Winsemius
> Cc: r-help at r-project.org
> Subject: Re: [R] Match ISO 8601 week-of-year numbers to month-of-year
> numbers on Windows with German locale
> 
> Aye, but this:
> 
>   some_dates <- as.POSIXct(c("2015-12-24", "2015-12-31", "2016-01-01",
> "2016-01-08"))
> 
>   (year_week <- format(some_dates, "%Y-%U"))
>   ## [1] "2015-51" "2015-52" "2016-00" "2016-01"
> 
>   (year_week_day <- sprintf("%s-1", year_week))
>   ## [1] "2015-51-1" "2015-52-1" "2016-00-1" "2016-01-1"
> 
>   (as.POSIXct(year_week_day, format = "%Y-%U-%u"))
>   ## [1] "2015-12-21 EST" "2015-12-28 EST" "2016-01-04 EST" "2016-01-04 EST"
> 
> works fine on macOS & Linux (Ubuntu, anyway), but it fails on Windows (10,
> 64bit, R 3.3.2):
> 
>   (as.POSIXct(year_week_day, format = "%Y-%U-%u"))
>   ## [1] "2015-12-21 PST" "2015-12-28 PST" NA               "2016-01-04 PST"

Why do you say it works fine on Ubuntu?  The date "2016-01-01" is in week 0 of 2016.  There is no Monday in week 0.  So I would argue the return  value of NA from Windows is more appropriate than returning the date of Monday in week 1 of 2016 like Ubuntu does.

Dan

Daniel Nordlund, PhD
Research and Data Analysis Division
Services & Enterprise Support Administration
Washington State Department of Social and Health Services

> 
> On 1/12/17, David Winsemius <dwinsemius at comcast.net> wrote:
> >
> >> On Jan 12, 2017, at 8:14 AM, Janko Thyson <janko.thyson at gmail.com>
> wrote:
> >>
> >> Dear list,
> >>
> >> I'm experiencing problems with converting strings of the format
> >> "YYYY-<weekofyear>" (e.g. 2016-01, 2016-52) to proper POSIX dates
> >> which (I
> >> think) I need in order to retrieve the month-of-the-year number.
> >>
> >> Simpler put: I'd like to match week-of-the-year numbers to
> >> month-of-the-year numbers. Ideally, the week-of-the-year number
> would
> >> follow the ISO 8601 convention (i.e. format argument "%V") instead of
> >> the US (format argument "%U") or UK (format argument "%W")
> convention.
> >>
> >> After posting this to Stackoverflow, I have strong reasons to believe
> >> that the issue is caused by Windows:
> >> http://stackoverflow.com/questions/41616407/match-iso-8601-week-
> numbe
> >> rs-to-month-of-year-on-windows-with-german-
> locale/41617215?noredirect
> >> =1#comment70436768_41617215
> >>
> >> Example:
> >>
> >> # ISO 8601 convention:
> >>
> >> (yw <- format(posix, "%Y-%V"))
> >
> > The documentation for R datetime format parameters ?strptime says %V
> > is ignored on input.
> >
> >
> >> # [1] "2015-52" "2015-53" "2016-53" "2016-01"
> >> ywd <- sprintf("%s-1", yw)(as.POSIXct(ywd, format = "%Y-%V-%u"))
> >
> > The documentation for R datetime format parameters ( = ?strptime) says
> > %V is ignored on input.
> >
> > You should leartn to post plain text to r-help.
> >
> > --
> > David.
> >
> >
> >> # [1]
> >> "2015-01-12 CET" "2015-01-12 CET" "2016-01-12 CET" "2016-01-12 CET"#
> >> -> utterly wrong!!!
> >>
> >> # US convention:
> >> (yw <- format(posix, "%Y-%U"))# [1] "2015-51" "2015-52" "2016-00"
> >> "2016-01"
> >> ywd <- sprintf("%s-1", yw)(as.POSIXct(ywd, format = "%Y-%U-%u"))# [1]
> >> "2015-12-21 CET" "2015-12-28 CET" NA               "2016-01-04 CET"#
> >> -> NA problem for week 00A fellow R user tested this on both macOS
> >> -> and
> >> Ubuntu and he didn't encounter the issue:
> >>
> >> some_dates <- as.POSIXct(c("2015-12-24", "2015-12-31", "2016-01-01",
> >> "2016-01-08"))
> >> (year_week <- format(some_dates, "%Y %U"))## [1] "2015 51" "2015 52"
> >> "2016 00" "2016 01"
> >> (year_week_day <- sprintf("%s 1", year_week))## [1] "2015 51 1" "2015
> >> 52 1" "2016 00 1" "2016 01 1"
> >> (as.POSIXct(year_week_day, format = "%Y %U %u"))## [1] "2015-12-21
> >> EST" "2015-12-28 EST" "2016-01-04 EST" "2016-01-04 EST"
> >>
> >> My session info:
> >>
> >>> sessionInfo()
> >> R version 3.3.2 (2016-10-31)
> >> Platform: x86_64-w64-mingw32/x64 (64-bit) Running under: Windows >=
> 8
> >> x64 (build 9200)
> >>
> >> locale:[1] LC_COLLATE=German_Germany.1252
> >> LC_CTYPE=German_Germany.1252
> LC_MONETARY=German_Germany.1252
> >> [4] LC_NUMERIC=C                       LC_TIME=English_United
> >> States.1252
> >>
> >> attached base packages:[1] stats     graphics  grDevices utils
> >> datasets  methods   base
> >>
> >> other attached packages:
> >> [1] fva_0.1.0       digest_0.6.10   readxl_0.1.1    dplyr_0.5.0
> >> plyr_1.8.4      magrittr_1.5
> >> [7] memoise_1.0.0   testthat_1.0.2  roxygen2_5.0.1  devtools_1.12.0
> >>
> >> loaded via a namespace (and not attached):
> >> [1] Rcpp_0.12.8     lubridate_1.6.0 assertthat_0.1  packrat_0.4.8-1
> >> crayon_1.3.2    withr_1.0.2
> >> [7] R6_2.2.0        DBI_0.5-1       stringi_1.1.2   rstudioapi_0.6
> >> tools_3.3.2     stringr_1.1.0  [13] tibble_1.2
> >>
> >> Any idea on how to workaround this issue on Windows?
> >>
> >> Thanks and best regards,
> >>
> >> Janko Thyson
> >>
> >> 	[[alternative HTML version deleted]]
> >>
> >> ______________________________________________
> >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >> 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
> > Alameda, CA, USA
> >
> > ______________________________________________
> > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > 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.
> >
> 