Sorry, there's a mistake, there's a missing comma, it should be df[df$date >= '2012-01-01'& df$date <= '2013-12-31', ]$A
Rui Barradas Citando ruipbarra...@sapo.pt: > Hello, > > Try > > df[df$date >= '2012-01-01'& df$date <= '2013-12-31']$A = etc > > Hope this helps, > > Rui Barradas > > > Citando lily li <chocol...@gmail.com>: >> Hi R users, >> >> I have a data frame, and I generate a date column like this: >> df$date = seq(as.Date('2012-01-01'), as.Date('2014-12-31')) >> >> df >> A B C >> 1 2 1 >> 2 2 3 >> 3 2 4 >> >> So the data frame has 4 columns now. But when I want to change the values >> of column A for specific dates, such as 2012-01-01 to 2013-12-31, I use the >> code below: >> df[date >= '2012-01-01'&date <= '2013-12-31']$A = >> df[date >= '2012-01-01'&date <= '2013-12-31']$A +2 >> >> But it does not work, the date I generate seems not effective. What is the >> problem? Thanks for your help. >> >> [[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.htmland provide commented, >> minimal, self-contained, reproducible code. > > > > [[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.htmland provide commented, > minimal, self-contained, reproducible code. [[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.