R help - Nov 2008 - How can I access the list argument within a "for" function call

Greetings,

I have been playing around with the R/Parallel package, which can farm out the
computation of a for-loop among multiple worker processes.  Each worker gets a
chunk of the for-loop iterations; for example, if you have two workers and for(x
in 1:1000){...}, one worker would typically get iterations 1:500, while the
second does 501:1000.

I would like to be able to preallocate matrices to capture the results within
the for loop, on the first iteration.  Is there a way to access the list
argument of the "for" function programmatically from within the loop? 
I am referring to the for arguments shown on page 51 of the R Language
Definition manual:

   "for"(var,list,expr)

I think I have a work-around, but was curious whether this was possible...

Thanks,
Mike


	[[alternative HTML version deleted]]

I am not sure exactly what you mean with your question.  If you have a
named list and want to access the 'name' within the 'for' along
with
the value, then you can do something like this:

for (i in names(myList)){
    value <- myList[[i]]   # get the values
    plot(values, main=paste("Plot of", i))
}

A little more clarification is need on your question.

On Fri, Nov 21, 2008 at 3:30 PM, Mike Rowe <miker at tethysbio.com>
wrote:
> Greetings,
>
> I have been playing around with the R/Parallel package, which can farm out
the computation of a for-loop among multiple worker processes.  Each worker gets
a chunk of the for-loop iterations; for example, if you have two workers and
for(x in 1:1000){...}, one worker would typically get iterations 1:500, while
the second does 501:1000.
>
> I would like to be able to preallocate matrices to capture the results
within the for loop, on the first iteration.  Is there a way to access the list
argument of the "for" function programmatically from within the loop? 
I am referring to the for arguments shown on page 51 of the R Language
Definition manual:
>
>   "for"(var,list,expr)
>
> I think I have a work-around, but was curious whether this was possible...
>
> Thanks,
> Mike
>
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?