[R-gui] ggraphics and retrieving mouse coordinate as npc coordinates

[Mark Heckmann]

Hi all,

i tried to retrieve the mouse coordinates from a ggraphics widget  
using a handler. With base graphics system it works fine, but using  
grid, the returned values do not make sense to me. How can I transform  
the returned values to e.g. npc coordinates?

	library(RGtk2)
	library(gWidgets)

	w = gwindow("ggraphics example")
	g = ggraphics(cont=w, expand=T)
	size(g) <- c(900,900)
	Sys.sleep(1)
	print(grid.rect())

	addHandlerClicked(g, handler = function(h,...) {
   		x <- h$x; y <- h$y
		print(c("pressed at:", c(x,y)))
	})	

Thanks and merry X-mas
Mark

–––––––––––––––––––––––––––––––––––––––
Mark Heckmann
Dipl. Wirt.-Ing. cand. Psych.
Vorstraße 93 B01
28359 Bremen
Blog: www.markheckmann.de
R-Blog: http://ryouready.wordpress.com