Hi r-help-boun...@r-project.org napsal dne 01.07.2011 14:32:31:
> B Marktplaats <gm.spam2...@gmail.com> > Odeslal: r-help-boun...@r-project.org > > 01.07.2011 14:32 > > Komu > > r-help@r-project.org > > Kopie > > Předmět > > [R] defining new variable > > Hello, > > I'm new to R and I'm trying to define new quite simple variable but I'm > struggling with R syntax (when coming to dates) for a while and still > getting <errors> on it. > > I would be very grateful if someone could help me with this, to be able to > move on. > > I have the following variables: > > - Transplant.date > - Faildate > - Death.date > > The new variable Time should do the following thing: > > Time <- > > If Not IsNull(<Faildate>) Then DaysBetween(<transplant date> ,<Faildate>) > Else If IsNull(<Faildate>) And Not IsNull(<Death date>) Then > DaysBetween(<transplant date> ,<Death date>) Else If IsNull(<Faildate>) And > IsNull(<Death date>) Then DaysBetween(<transplant date> ,CurrentDate()) I bet there is more elegant solution but with such data frame you can > df td fd dd 1 2011-06-11 2011-06-16 <NA> 2 2011-06-12 <NA> 2011-06-22 3 2011-06-13 <NA> 2011-06-23 4 2011-06-14 <NA> 2011-06-24 5 2011-06-15 <NA> <NA> df$days<-rowSums(sapply(df[,2:3], "-", df$td), na.rm=T) Then you can check for NA values in fd and dd and change respective values by df$days[rowSums(is.na(df[,2:3]))==2] <- Sys.Date()-df$td[rowSums(is.na(df[,2:3]))==2] df td fd dd days 1 2011-06-11 2011-06-16 <NA> 5 2 2011-06-12 <NA> 2011-06-22 10 3 2011-06-13 <NA> 2011-06-23 10 4 2011-06-14 <NA> 2011-06-24 10 5 2011-06-15 <NA> <NA> 16 > Regards Petr > > > > > Thank you very much!! > > Laura > > [[alternative HTML version deleted]] > > ______________________________________________ > 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.