R help - Jun 2011 - txtProgressBar and parallelized foreach

Hi all,

I can create a text-progress bar in a foreach loop by the following code :

n=10
foreach( i = 1:n ,.combine=c) %do%{
	setTxtProgressBar(pb, i)
	Sys.sleep(0.1)
}


However, once i use the parallelized foreach, the text-progress bar
disappear.  Any solution to this problem? How can i create a progress
bar in parallelized foreach? Thanks

cl<-makeCluster(core)
registerDoSNOW(cl)

pb<-txtProgressBar(min = 0, max = n, style = 3)
foreach( i = 1:n ,.combine=c) %dopar%{
	setTxtProgressBar(pb, i)
	Sys.sleep(0.1)
}
close(pb)
stopCluster(cl)


Regards,
TszKin Julian

I think you do not understand how the parallelization works: Different 
iterations from your foreach() are run on different nodes, hence you 
change the progressbar on the node rather on the master in your loop.

Uwe Ligges


On 14.06.2011 12:23, Julian TszKin Chan wrote:
> Hi all,
>
> I can create a text-progress bar in a foreach loop by the following code :
>
> n=10
> foreach( i = 1:n ,.combine=c) %do%{
> 	setTxtProgressBar(pb, i)
> 	Sys.sleep(0.1)
> }
>
>
> However, once i use the parallelized foreach, the text-progress bar
> disappear.  Any solution to this problem? How can i create a progress
> bar in parallelized foreach? Thanks
>
> cl<-makeCluster(core)
> registerDoSNOW(cl)
>
> pb<-txtProgressBar(min = 0, max = n, style = 3)
> foreach( i = 1:n ,.combine=c) %dopar%{
> 	setTxtProgressBar(pb, i)
> 	Sys.sleep(0.1)
> }
> close(pb)
> stopCluster(cl)
>
>
> Regards,
> TszKin Julian
>
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