R help - Mar 2005 - how to capture a series of plots

Hi, there

I am trying to capture a series of plots into jpeg or png files so that I 
can create gif animation later. However, my plot background generation is 
very slow, and I create the background plot only at the very beginning, and 
at each step I only refresh the foreground points and symbols like this:
plot(x,y)
while (condition holds){
symbols(...add=1);
}

My question is, can I create a series of plots test1.jpg, 
test2.jpg...continuously? To my knowledge, R has to close current device (by 
dev.off()) to write to current file, so once first jpeg file is written, the 
current device with background will be off, therefore, I cannot add symbols 
in next device and create following file series.

Any suggestions?

Thanks

WC

See ?dev.copy

Uwe Ligges

Weijie Cai wrote:
> Hi, there
> 
> I am trying to capture a series of plots into jpeg or png files so that 
> I can create gif animation later. However, my plot background generation 
> is very slow, and I create the background plot only at the very 
> beginning, and at each step I only refresh the foreground points and 
> symbols like this:
> plot(x,y)
> while (condition holds){
> symbols(...add=1);
> }
> 
> My question is, can I create a series of plots test1.jpg, 
> test2.jpg...continuously? To my knowledge, R has to close current device 
> (by dev.off()) to write to current file, so once first jpeg file is 
> written, the current device with background will be off, therefore, I 
> cannot add symbols in next device and create following file series.
> 
> Any suggestions?
> 
> Thanks
> 
> WC
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! 
> http://www.R-project.org/posting-guide.html