Hi there! I have two date columns in a dataframe I need to selectively collapse based on missing values and which date comes first (imported from an text file). This is what I did:
RHSSP$CT <- as.POSIXct(RHSSP$CT, format='%m/%d/%y %H:%M') RHSSP$MRI <- as.POSIXct(RHSSP$MRI, format='%m/%d/%y %H:%M') RHSSP$Scan <- ifelse(is.na(RHSSP$MRI),RHSSP$CT,ifelse(is.na(RHSSP$CT),RHSSP$MRI,ifelse(RHSSP$CT>RHSSP$MRI,RHSSP$MRI,RHSSP$CT))) RHSSP$CT and RHSSP$MRI remain properly formatted (e.g.: "2011-06-21 22:31:00 PDT") BUT RHSSP$Scan does not (e.g.: 1294076700) I can't figure out how to maintain the proper format during the replacement. Looks like the replacement inherits the ifelse comparison format. Any suggestions? Many thanks Jon -- View this message in context: http://r.789695.n4.nabble.com/preserving-date-formats-in-functions-tp4632435.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.