As Peter said, matplot plots matrices. The columns of a matrix are vectors of numbers. A POSIXlt object is not a vector of numbers, it is a list. So it shouldn't work. And should not be expected to work.
But with a POSIXct object it will work. x <- strptime(as.character(x), format="%Y-%m-%d") ## [1] "POSIXt" "POSIXlt" matplot( as.POSIXct(x), y) At 1:56 PM +0100 12/7/06, [EMAIL PROTECTED] wrote: >Hi, > >Matplot works with x being Date class but not POSIXt. Here is the >example with R version 2.5.0 Under development (unstable) (2006-12-06 >r40129) > >Example: > >x <- Sys.Date() - c(1:10) >y <- cbind(1:10, 10:1) >class(x) >## [1] "Date" >matplot(x, y) > >x <- strptime(as.character(x), format="%Y-%m-%d") >## [1] "POSIXt" "POSIXlt" >matplot(x, y) >Error in matplot(x, y) : 'x' and 'y' must have only 1 or the same number >of columns > >Additionally, matplot with x being Date class does not use apropriate >annotation for x axis. This is very easy to obtain: # x is a Date object matplot(x,y,xaxt='n') axis.Date(1,x) or # x is a POSIXlt object matplot( as.POSIXct(x), y,xaxt='n') axis.POSIXct(1,x) So easy, in fact, that I personally would not expect R core to spend time on it. One of the virtues of R is that the language is so rich that little tweaks like this are often very easy. > >Thank you! > >Gregor > -Don -- -------------------------------------- Don MacQueen Environmental Protection Department Lawrence Livermore National Laboratory Livermore, CA, USA ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
