On Thu, 2009-08-20 at 08:14 +0100, Liviu Andronic wrote: > Dear R users > I would like to do some spreadsheet style expansion of dates. For > example, I would need to obtain a vector of months. I approached in an > obviously wrong way: > > paste(01:12) > [1] "1" "2" "3" "4" "5" "6" "7" "8" "9" "10" "11" "12" > > as.Date(paste(01:12), "%m") > [1] NA NA NA NA NA NA NA NA NA NA NA NA > > to subsequently format(.., "%b"). Other than writing the months > manually, could anyone suggest an easier way to obtain such a list? > Liviu
I think as.Date is probably not the best way to approach this as these aren't really dates - all you have is the month. R has some built in constants, including the abbreviated month names. See ?month.abb : mon <- 01:12 mon <- factor(mon, labels = month.abb) mon as.character(mon) ## it you want these as strings not a factor Notice also that starting from characters doesn't get the right answer. Compare mon above with the output from below. mon2 <- as.character(01:12) mon2 <- factor(mon2, labels = month.abb) mon2 With mon, using the month numbers as numerics keeps the ordering. If your data are characters, then replace the first line in the mon example with (something like): mon <- as.numeric(my.months) where my.months is your vector of months. FYI, should you need the full names at any point, there is another constant 'month.name' that fulfils that requirement. See ?month.abb G -- %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% Dr. Gavin Simpson [t] +44 (0)20 7679 0522 ECRC, UCL Geography, [f] +44 (0)20 7679 0565 Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk Gower Street, London [w] http://www.ucl.ac.uk/~ucfagls/ UK. WC1E 6BT. [w] http://www.freshwaters.org.uk %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% ______________________________________________ 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.
