Plot availability

I really would encourage you to look at ggplot2 before trying to
create something of your own.  Your example would convert to the
following ggplot2 code:

df <- data.frame(x = 0:3, y = 3:0)

plot <- ggplot() + xlim(-3, 3) + ylim(-3, 3) + opts(main = "Hello World")
plot + geom_line(aes(x=x, y=y), df, colour = "blue")

Hadley

On Fri, Sep 19, 2008 at 1:44 PM, john crepezzi <seejohnrun at gmail.com> wrote:

I believe I've found a way to wrap and use dev.cur()[[1]] to have the
desired effect.  I'm just leaving my terminal now, but I'll post these
results on monday so everyone can see how it turned out.

If you have any ideas or qualms with this method, please let me
know.

Thanks Duncan!
--john

On Sep 19, 2:00 pm, john crepezzi <seejohn... at gmail.com> 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 <murd... at stats.uwo.ca> 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.

Duncan Murdoch

--
http://had.co.nz/