Hi: You could try the lubridate package:
library(lubridate) week(weekly$week) week(july4) [1] 27 27 > week function (x) yday(x)%/%7 + 1 <environment: namespace:lubridate> which is essentially Gabor's code :) HTH, Dennis On Tue, Aug 2, 2011 at 7:36 AM, Dimitri Liakhovitski <dimitri.liakhovit...@gmail.com> wrote: > Hello! > > I have dates for the beginning of each week, e.g.: > weekly<-data.frame(week=seq(as.Date("2010-04-01"), > as.Date("2011-12-26"),by="week")) > week # each week starts on a Monday > > I also have a vector of dates I am interested in, e.g.: > july4<-as.Date(c("2010-07-04","2011-07-04")) > > I would like to flag the weeks in my weekly$week that contain those 2 > individual dates. > I can only think of a very clumsy way of doing it: > > myrows<-c(which(weekly$week==weekly$week[weekly$week>july4[1]][1]-7), > which(weekly$week==weekly$week[weekly$week>july4[2]][1]-7)) > weekly$flag<-0 > weekly$flag[myrows]<-1 > > It's clumsy - because actually, my vector of dates of interest (july4 > above) is much longer. > Is there maybe a more elegant way of doing it? > Thank you! > -- > Dimitri Liakhovitski > marketfusionanalytics.com > > ______________________________________________ > R-help@r-project.org mailing list > 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. > ______________________________________________ R-help@r-project.org mailing list 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.