Hi, Gabor It works now, thanks. The tricky part is I imported my data from Excel and converted the data into POSIXct format using command strptime(). So I thought they were already converted into dates and times class. I added as.POSIct, now it works alright.
Thanks for that Gabor Grothendieck wrote: > When I try this: > > >> x <- as.POSIXct(Sys.Date() + 0:9) >> plot(x, x) >> plot(x ~ x) >> > > The first one does give me dates on both axes but the second one gives > numbers on the Y axis. > > Note that you can always not print the axis with plot and then do it yourself > with axis or Axis. This works for me: > > >> plot(x ~ x, yaxt = "n") >> Axis(x, side = 2) >> > > >> R.version.string # Windows Vista >> > [1] "R version 2.6.1 Patched (2007-12-06 r43610)" > > On Jan 14, 2008 6:37 PM, Jingru Dai <[EMAIL PROTECTED]> wrote: > >> Hi, everyone >> >> I've been trying to make a scatter plot of POSIXct format data to see >> the difference between two start time. >> Like X: >> [1] "1995-05-26 19:00:00" "1995-05-27 01:00:00" "1995-05-27 07:00:00" >> [4] "1995-06-29 01:00:00" "1995-06-29 07:00:00" "1995-06-30 13:00:00" >> [7] "1995-06-30 19:00:00" "1995-07-01 01:00:00" "1995-07-01 07:00:00" >> ...... >> Y: >> [1] "1995-05-26 19:00:00" "1995-05-27 01:00:00" "1995-05-27 07:00:00" >> [4] "1995-06-29 01:00:00" "1995-06-29 07:00:00" "1995-06-30 13:00:00" >> [7] "1995-06-30 19:00:00" "1995-07-01 01:00:00" "1995-07-01 07:00:00" >> ....... >> >> But it seems plot(x,y) doesn't work, y have to be numeric format. Is >> there any special command for that or I should change the format of the >> data? >> Thanks >> >> Jingru Dai >> ---- >> School of Mathematical Sciences >> Rm 454, Building 28 >> Monash University, 3800 >> Victoria, Australia >> >> ______________________________________________ >> 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.
