[R-sig-hpc] foreach() with 'lapply'?

Brian G. Peterson brian at braverock.com
Thu Jul 21 19:44:56 CEST 2011

On Thu, 2011-07-21 at 10:27 -0700, Megh Dal wrote:
> Dear all, I was exploring the "dopar" mechanism in foreach package, however it seems that "dopar" can be applied only in place of 'for' loop. Here my question is: can it be used with 'lapply' construct?
> I have a big 'list' object and I am in some process to apply some complex custom made function on each element of that 'list' object. I have dual core windows vista system, and planning to break that list into 2 part of equal length, then apply that function simultaneously using both cores.
> Can somebody throw some light how to achieve that?

Please read the documentation before posting.

foreach iterates over some iterator, as described in the package
vignette here:

and that iterator may easily be a list.  In that case, foreach looks
very much like lapply.  

foreach will also, by default, return a list.  See the documentation
for .combine.

If you need additional help, please provide a minimal self-contained
example, per the posting guide.


   - Brian

Brian G. Peterson
Ph: 773-459-4973
IM: bgpbraverock

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