Dear Tim, > -----Original Message----- > From: r-devel-boun...@r-project.org [mailto:r-devel-boun...@r-project.org] On > Behalf Of Tim Triche, Jr. > Sent: October-07-11 3:05 PM > To: Prof Brian Ripley > Cc: r-devel > Subject: Re: [Rd] parallel::mclapply() dummy function on Windows? > > On Thu, Oct 6, 2011 at 11:25 PM, Prof Brian Ripley > <rip...@stats.ox.ac.uk>wrote: > > > > > Why would it make it easier? And how could using a dummy for 'most users' > > (who are on Windows) offer them 'good parallel support'? > > > Good point. Most of my users are on unix, because my use of mclapply() is > primarily to expedite processing of raw scanner data. Only a handful of > users for the packages that call mclapply() are on Windows. Right now, I > default to having parallel=FALSE flags all over the place, but I'd prefer for > the default to be "go as fast as practical in the common case", i.e., Unix. > It would have been more accurate for me to say "I would like to parallelize > by default, without having the methods fail on Windows in the default > configuration" than to claim that I want "good parallel support" for Windows. > When I have tried using the foreach/doMC combination in the past, it has not > worked out satisfactorily, so I don't know how well I can support Windows > users... period.
Why don't you just apply the approach you initially suggested in your own package, defining mclapply() the way you want it? I hope this helps, John > > Take a look at e.g. package 'boot' to see how to offer alternatives. (A > > version that uses 'parallel' is pending on CRAN, or see > > http://www.stats.ox.ac.uk/pub/**R/boot_1.3-3.tar.gz<http://www.stats.o > > x.ac.uk/pub/R/boot_1.3-3.tar.gz>.) Package 'parallel' may in future > > offer a higher-level abstraction layer that makes offers such a choice, but > as the 'boot' code shows, deciding what to send to the workers in a snow- > style cluster is not simple. > > > > It seems similar to what I do (off topic: why do you use the file extension > '.q' for all of the R/S code files?): pass flags around. I suppose I was > just being lazy, but I would love to default to "go as fast as possible" > without having Windows users get left out in the cold (unless they add flags > to their function calls). > > Thank you for your suggestions, I will look into this further. > > -- > Tim Triche, Jr. > USC Biostatistics > > [[alternative HTML version deleted]] > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
