Untested, try this: as.Date(as.character(dat_FF$date), format = "%Y%m")
If that doesn't work, let me know. Michael On Oct 22, 2011, at 4:26 PM, "Martin Spindler" <[email protected]> wrote: > Dear all, > > I would like to convert the first column of a dataframe to a date (original > format: year (4 digits) and month (last 2 digits)) > >> str(dat_FF) > 'data.frame': 1022 obs. of 4 variables: > $ date : int 192607 192608 192609 192610 192611 192612 192701 192702 > 192703 192704 ... > $ Rm.Rf: num 2.69 2.52 0 -3.06 2.42 2.66 0 4.29 0.51 0.57 ... > $ SMB : num -2.49 -1.25 -1.38 -0.2 -0.34 -0.07 -0.11 0.35 -1.87 0.44 ... > $ HML : num -2.91 4.25 0.22 0.71 -0.4 -0.11 4.92 3.17 -2.92 1.33 ... > > But > >> dat_FF$date <- as.Date(as.character(dat_FF$date), format="%Y%m") > > delievers NAs: > >> str(dat_FF) > 'data.frame': 1022 obs. of 4 variables: > $ date : Date, format: NA NA ... > > I am very grateful for hints! Thanks in advance! > > Best, > > Martin > > ______________________________________________ > [email protected] 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. ______________________________________________ [email protected] 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.
