R help - Jun 2010 - Windows, OSX and Linux: updating a graphic device and double buffering

Hello there,

I'm struggling with the base graphics system on different
operating systems.

I would like to get an animation effect by re-plotting with the plot 
function. See the attached code example: move the slider
quick from one side to the other.

I experience different levels of success, depending on which OS I use.

- Linux (Ubuntu >9.10, R 2.9.2-3): Each plot command gets displayed.
However the labels are flickering.

- Windows: works perfect, double buffering is really well implemented.

- OS X: Moving the slider slowly results in displaying the output of
almost all plot commands. However if you move the slider quickly, only 
few of the plot commands get displayed (the orange bullet jumps).

This question has been asked before, but hopefully things have changed: 
Is it possible to double buffer my output manually?

If not, is it possible to force update my graphic device. E.g. with a 
command like dev.flush()?

How can I run my code on all operating systems without any "jumps"?

Regards,

Adrian Waddell


Here is a minimal example code:

library(tcltk)
tt <- tktoplevel()
tkpack(top <- tkframe(tt), side = "top")
SliderValue <- tclVar("50")
SliderValueLabel <- tklabel(top,text=as.character(tclvalue(SliderValue)))
tkpack(tklabel(top,text="Slider Value : "),SliderValueLabel, side =
"left")
tkconfigure(SliderValueLabel,textvariable=SliderValue)
slider <- tkscale(tt, from=0, to=100,
		showvalue=F, variable=SliderValue,
		resolution=1, orient="horizontal", length = 200)
tkpack(slider, side = "top")
tkconfigure(slider, command=function(...){
			state <- unlist(...)
			myPlotFn(state)
		})

myPlotFn <- function(state) {
	plot(1,1, type = 'n', xlim = c(-10,110), ylim = c(-2,2))
	lines(c(0,100), c(0,0), lwd=4)
	points(as.numeric(tclvalue(SliderValue)),0, cex = 10, pch = 19, col = 
"orange")
}

I'm looking for answers to your questions as well. Has double
buffering been really implemented for Windows? I cannot find any
announcement in the NEWS or ONEWS or OONEWS file in svn, although it
looks Windows graphics devices perform much better than Linux
x11()/Mac OS quartz().

It looks the Graphics task view needs to be updated too if double
buffering is already implemented:
http://cran.r-project.org/web/views/Graphics.html

Regards,
Yihui
--
Yihui Xie <xieyihui at gmail.com>
Phone: 515-294-2465 Web: http://yihui.name
Department of Statistics, Iowa State University
2215 Snedecor Hall, Ames, IA



On Fri, Jun 11, 2010 at 11:28 AM, Adrian Waddell <adrian at waddell.ch>
wrote:
> Hello there,
>
> I'm struggling with the base graphics system on different
> operating systems.
>
> I would like to get an animation effect by re-plotting with the plot
> function. See the attached code example: move the slider
> quick from one side to the other.
>
> I experience different levels of success, depending on which OS I use.
>
> - Linux (Ubuntu >9.10, R 2.9.2-3): Each plot command gets displayed.
> However the labels are flickering.
>
> - Windows: works perfect, double buffering is really well implemented.
>
> - OS X: Moving the slider slowly results in displaying the output of
> almost all plot commands. However if you move the slider quickly, only few
> of the plot commands get displayed (the orange bullet jumps).
>
> This question has been asked before, but hopefully things have changed: Is
> it possible to double buffer my output manually?
>
> If not, is it possible to force update my graphic device. E.g. with a
> command like dev.flush()?
>
> How can I run my code on all operating systems without any
"jumps"?
>
> Regards,
>
> Adrian Waddell
>
>
> Here is a minimal example code:
>
> library(tcltk)
> tt <- tktoplevel()
> tkpack(top <- tkframe(tt), side = "top")
> SliderValue <- tclVar("50")
> SliderValueLabel <-
tklabel(top,text=as.character(tclvalue(SliderValue)))
> tkpack(tklabel(top,text="Slider Value : "),SliderValueLabel, side
= "left")
> tkconfigure(SliderValueLabel,textvariable=SliderValue)
> slider <- tkscale(tt, from=0, to=100,
> ? ? ? ? ? ? ? ?showvalue=F, variable=SliderValue,
> ? ? ? ? ? ? ? ?resolution=1, orient="horizontal", length = 200)
> tkpack(slider, side = "top")
> tkconfigure(slider, command=function(...){
> ? ? ? ? ? ? ? ? ? ? ? ?state <- unlist(...)
> ? ? ? ? ? ? ? ? ? ? ? ?myPlotFn(state)
> ? ? ? ? ? ? ? ?})
>
> myPlotFn <- function(state) {
> ? ? ? ?plot(1,1, type = 'n', xlim = c(-10,110), ylim = c(-2,2))
> ? ? ? ?lines(c(0,100), c(0,0), lwd=4)
> ? ? ? ?points(as.numeric(tclvalue(SliderValue)),0, cex = 10, pch = 19, col
> "orange")
> }
>