R help - Oct 2004 - changing coordinate systems

Hi, All.  I am working with some eye-tracking data.  I have a graph I
generate in R with arbitrary plotting commands which I want to
display.  Then I want to plot the eyetracking data overlayed on it.

The eye-tracking data is in x-y coordinates on a 640x480 coordinate
system.  Ideally, what I'd like to do is plot my R graph (e.g.,
plot(1:10)), and then change the complete coordinate system of the
whole device to be 640x480.  commands like plot.window() don't work
because that just changes the coordinate system of the plotable area,
not the whole device or viewable image (ie, the x labels aren't
right).

Any ideas?

thanks!
greg

On Thu, 28 Oct 2004, Greg Trafton wrote:
> Hi, All.  I am working with some eye-tracking data.  I have a graph I
> generate in R with arbitrary plotting commands which I want to
> display.  Then I want to plot the eyetracking data overlayed on it.
> 
> The eye-tracking data is in x-y coordinates on a 640x480 coordinate
> system.  Ideally, what I'd like to do is plot my R graph (e.g.,
> plot(1:10)), and then change the complete coordinate system of the
> whole device to be 640x480.  commands like plot.window() don't work
> because that just changes the coordinate system of the plotable area,
> not the whole device or viewable image (ie, the x labels aren't
> right).
> 
> Any ideas?
?par, especially usr (to set the plot coords) and mai (to remove the 
margins)
> plot(1:10)
> par(mai=rep(0,4))
> par(usr=c(0,640,0,480))
> rect(10, 10, 630, 470)
shows the idea

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
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