Michael, If you have a big.matrix, you just want to iterate over the rows. I'm not in R and am just making this up on the fly (from a bar in Beijing, if you believe that):
foreach(i=1:nrow(x),.combine=c) %dopar% f(x[i,]) should work, essentially applying the functin f() to the rows of x? But perhaps I misunderstand you. Please feel free to email me or Mike ( michael.k...@yale.edu) directoy with questions about bigmemory, we are very interested in applications of it to real problems. Note that the package foreach uses package iterators, and is very flexible, in case you need more general iteration in parellel. Regards, Jay Original message: Hi there! I have become a big fan of the 'foreach' package allowing me to do a lot of stuff in parallel. For example, evaluating the function f on all elements in a vector x is easily accomplished: foreach(i=1:length(x),.combine=c) %dopar% f(x[i]) Here the .combine=c option tells foreach to combine output using the c()-function. That is, to return it as a vector. Today I discovered the 'bigmemory' package, and I would like to contruct a big.matrix in a parralel fashion row by row. To use foreach I see no other way than to come up with a substitute for c in the .combine option. I have checked out the big.matrix manual, but I can't find a function suitable for just that. Actually, I wouldn't even know how to do it for a usual matrix. Any clues? Thanks! -- Michael Knudsen micknud...@gmail.com http://lifeofknudsen.blogspot.com/ -- John W. Emerson (Jay) Associate Professor of Statistics Department of Statistics Yale University http://www.stat.yale.edu/~jay [[alternative HTML version deleted]] ______________________________________________ R-help@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.
