这与我的问题直接相关来自每周时间格式的日期的 POSIX 日期 https://stackoverflow.com/questions/41597604/posix-date-from-dates-in-weekly-time-format.
但是，在这个问题中我想特别询问如何映射ISO 8601 http://www.iso.org/iso/home/standards/iso8601.htm周数字到一年中的月份数字。
对我来说，这似乎是不可能的和/或涉及一些非直观的黑客（甚至这些也不能真正可靠地工作）并且因此，IMO 应被视为需要在基础 R 中修复的内容。如果我错了，请纠正我
编辑：似乎这个问题与在 Windows 上运行和/或您所在的区域设置密切相关（在我的例子中是标准德语）
posix <- as.POSIXct(c("2015-12-24", "2015-12-31", "2016-01-01", "2016-01-08"))
ISO 8601
(yw <- format(posix, "%Y-%V"))
# [1] "2015-52" "2015-53" "2016-53" "2016-01"
ywd <- sprintf("%s-1", yw)
(as.POSIXct(ywd, format = "%Y-%V-%u"))
# [1] "2015-01-12 CET" "2015-01-12 CET" "2016-01-12 CET" "2016-01-12 CET"
# -> utterly wrong!!!
ywd <- sprintf("%s-4", yw)
(as.POSIXct(ywd, format = "%Y-%V-%u"))
# -> still wrong -> the day of the week is not the reason
# -> no way to use ISO 8601 convention to map week of the year to month of the year
为了尽职调查：尝试使用美国或英国惯例时也是不可能的：
美国大会
(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 00
ywd <- sprintf("%s-4", yw)
# -> does not work for week 00
(as.POSIXct(ywd, format = "%Y-%U-%u"))
# The day of the week is not the reason
# -> no way to use this convention to reliably map week of the year to month of the year
英国大会
(yw <- format(posix, "%Y-%W"))
# [1] "2015-51" "2015-52" "2016-00" "2016-01"
ywd <- sprintf("%s-1", yw)
(as.POSIXct(ywd, format = "%Y-%W-%u"))
# [1] "2015-12-21 CET" "2015-12-28 CET" NA "2016-01-04 CET"
# -> NA problem for week 00
ywd <- sprintf("%s-4", yw)
# -> does not work for week 00
(as.POSIXct(ywd, format = "%Y-%W-%u"))
# The day of the week is not the reason
# -> no way to use this convention to reliably map week of the year to month of the year
会议信息
> 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
> devtools::session_info()
Session info -----------------------------------------------------------------------------------------------
setting value
version R version 3.3.2 (2016-10-31)
system x86_64, mingw32
ui RStudio (1.0.136)
language en
collate German_Germany.1252
tz Europe/Berlin
date 2017-01-12
Packages ---------------------------------------------------------------------------------------------------
package * version date source
assertthat 0.1 2013-12-06 CRAN (R 3.3.2)
crayon 1.3.2 2016-06-28 CRAN (R 3.3.2)
DBI 0.5-1 2016-09-10 CRAN (R 3.3.2)
devtools * 1.12.0 2016-06-24 CRAN (R 3.3.2)
digest * 0.6.10 2016-08-02 CRAN (R 3.3.2)
dplyr * 0.5.0 2016-06-24 CRAN (R 3.3.2)
fva * 0.1.0 <NA> local
lubridate 1.6.0 2016-09-13 CRAN (R 3.3.2)
magrittr * 1.5 2014-11-22 CRAN (R 3.3.2)
memoise * 1.0.0 2016-01-29 CRAN (R 3.3.2)
packrat 0.4.8-1 2016-09-07 CRAN (R 3.3.2)
plyr * 1.8.4 2016-06-08 CRAN (R 3.3.2)
R6 2.2.0 2016-10-05 CRAN (R 3.3.2)
Rcpp 0.12.8 2016-11-17 CRAN (R 3.3.2)
readxl * 0.1.1 2016-03-28 CRAN (R 3.3.2)
roxygen2 * 5.0.1 2015-11-11 CRAN (R 3.3.2)
stringi 1.1.2 2016-10-01 CRAN (R 3.3.2)
stringr 1.1.0 2016-08-19 CRAN (R 3.3.2)
testthat * 1.0.2 2016-04-23 CRAN (R 3.3.2)
tibble 1.2 2016-08-26 CRAN (R 3.3.2)
withr 1.0.2 2016-06-20 CRAN (R 3.3.2)
