On Fri, Sep 19, 2008 at 2:00 PM, john crepezzi <[EMAIL PROTECTED]> wrote: > I'm not so sure the original way I stated my issue was clear enough, > so I'll attempt to elaborate a little bit. > > I'd like to make a function that is passed the name of a plot object, > and a lines/point specification, and graphs them all on the same plot. > > I don't want to redraw the plot each time, and I don't want the code > to have any concept of a "first entry" instantiating the plot with > plot() in place of lines(). > > Ideally, I'd like something to the effect of: > > plot <- createPlot(main = "Hello World", sub = "tiny, little world", > xlim = c(-3, 3), ylim = c(-3, 3)) > > plot <- addElement(plot, lines(col = 'BLUE', x = c(0, 1, 2, 3), y = > c(3, 2, 1, 0))) > > Hopefully this laid my problem out a little better. > > Thanks in advance for any help you might be able to offer > -John Crepezzi > > On Sep 19, 10:11 am, Duncan Murdoch <[EMAIL PROTECTED]> wrote: >> On 9/19/2008 9:32 AM, john crepezzi wrote: >> >> > Is it possible to see if a plot is already open before I call lines()? >> >> I don't think so. You can see if a graphics device is open by looking >> at dev.cur(), but I don't think there's a test for plot.new(). I'd just >> wrap the call in try() if you're not sure it will work. >>
Using classic graphics try this: # classic graphics plot(BOD) p <- recordPlot() # some times go by and other plots are made plot(0) # now go back to the original plot and add more replayPlot(p) points(5, 15, col = "red") In lattice graphics its like this: # lattice graphics library(lattice) p <- xyplot(demand ~ Time, BOD) # some times go by and other plots are made plot(0) # now replot the original plot and add more plot(p) trellis.focus("panel", 1, 1) panel.points(5, 15, col = "red") trellis.unfocus() ggplot2 is also grid-based and should be amenable to this sort of thing too. ______________________________________________ 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.