Hi David, thanks for replying and sorry about the HTML/non-plain-text email (I forgot to change that, shouldn't have happened).
Might just be me, but reading "The documentation for R datetime format parameters ?strptime says %V is ignored on input." in the documentation doesn't really tell me all that much. As a user, I would read that, not completely understand what this means and thus try to understand it better by applying it in actual code: (yw <- format(posix, "%Y-%V")) > # [1] "2015-52" "2015-53" "2016-53" "2016-01" Which, after checking back with a calendar, would give me reason to believe that it using %V does in fact seem to work: it's an input to `format()` and R doesn't seem to ignore it as the correct week numbers (following ISO 8601) are returned. Not wanting to stress this particular aspect any further, though, I would slightly rephrase my original question: is it possible to use the ISO 8601 convention for weeknumbers at all (on Windows, using a German locale setting) and if so, how would I link ISO 8601 weeknumbers to the correct month of the year? Thanks for help, Janko On Thu, Jan 12, 2017 at 8:37 PM, David Winsemius <dwinsem...@comcast.net> wrote: > >> On Jan 12, 2017, at 8:14 AM, Janko Thyson <janko.thy...@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-numbers-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@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@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.