I will try that but I am somewhat skeptical since when I go class(date.of.birth) I get not just one word but two: "POSIXt" "POSIXct". Will that not mess up the logical test
When I tried the following: lapply(as.list(dataframename),class)=="POSIXt" every item was false Farrel Buchinsky GrandCentral Tel: (412) 567-7870 > > Dear Farrel, > Determine the class of each column and apply as.Date() just to those which > class is POSIX. For more details see ?class. Here is an example assuming > that you're data is named "mydata": > apply(mydata, 2, function(x) ifelse( class(x)=="POSIXt" | > class(x)=="POSIXlt" , as.Date(x) , x ) ) > > HTH, > > Jorge > > > > On Wed, Dec 10, 2008 at 6:26 PM, Farrel Buchinsky <[EMAIL PROTECTED]> wrote: >> >> converting a POSIX class variable to a date class is easy. >> dates<-as.Date(x) #where X is of class POSIX >> How does one do that to all columns in a data frame that are of POSIX >> class and leave all the other columns (integers, factors) as is. >> >> Feel free to reply with just one or two buzzwords that I could then >> search for to find how to do it. >> >> Farrel Buchinsky >> >> ______________________________________________ >> 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.
