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 <fjbuch at gmail.com> 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