On Thu, 08 Sep 2016, Veronica Andreo <veroand...@gmail.com> writes: > Hello list, > > Is there a quick way to get start and end date (%Y-%m-%d) from ISO > weeks if I only have dates? > > For example, I have this date in which some event happened: > "2010-08-21". Not only I want the ISO week, which I can obtain either > with isoweek (lubridate) or ISOweek (ISOweek), but I want the start > and end date of that ISO week. > > Do I need to print all ISO weeks from the period of interest and > sample there for start and end date? Or is there a better way to do > that? > > Thanks a lot in advance! > > Best, > Veronica
You could use a function like the following one (which assumes the start of the week is Monday and its end is Sunday): d <- c("2010-08-21", "2016-08-01") iso_start_end <- function(d) { d <- as.Date(d) wday <- as.POSIXlt(d)$wday data.frame(date = d, week = format(d, "%V"), starts = d - wday + 1, ends = d + 7 - wday) } iso_start_end(d) The function should produce this output: date week starts ends 1 2010-08-21 33 2010-08-16 2010-08-22 2 2016-08-01 31 2016-08-01 2016-08-07 -- Enrico Schumann Lucerne, Switzerland http://enricoschumann.net ______________________________________________ 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.