I received a warning about incompatible methods that I don't understand. The workaround in this example is simple.
What is the reason that these methods are seen as incompatible? Is there some dangerous consequence of my as.numeric() workaround? Can a fix to the code base, perhaps similar to my workaround, make this warning no longer necessary? I am using R 2.7.0 on Windows. version.string R version 2.7.0 (2008-04-22) Thanks Rich xlim <- as.Date(c("2005-04-09", "2007-09-07")) dx <- diff(xlim) xlim + c(-.02, .02)*dx ## correct answer and warning message xlim + as.numeric(c(-.02, .02)*dx) ## correct answer > xlim <- as.Date(c("2005-04-09", "2007-09-07")) > xlim [1] "2005-04-09" "2007-09-07" > dx <- diff(xlim) > dx Time difference of 881 days > xlim + c(-.02, .02)*dx ## correct answer and warning message [1] "2005-03-22" "2007-09-24" Warning message: Incompatible methods ("+.Date", "Ops.difftime") for "+" > xlim + as.numeric(c(-.02, .02)*dx) ## correct answer [1] "2005-03-22" "2007-09-24" > ______________________________________________ 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.