How do I parallelize in r on windows - example?
parallel-processing, r
Solution
Posting this because this took me bloody forever to figure out. Here's a simple example of parallelization in r that will let you test if things are working right for you and get you on the right path.
library(snow)
z=vector('list',4)
z=1:4
system.time(lapply(z,function(x) Sys.sleep(1)))
cl<-makeCluster(###YOUR NUMBER OF CORES GOES HERE ###,type="SOCK")
system.time(clusterApply(cl, z,function(x) Sys.sleep(1)))
stopCluster(cl)
You should also use library doSNOW to register foreach to the snow cluster, this will cause many packages to parallelize automatically. The command to register is `registerDoSNOW(cl)` (with `cl` being the return value from `makeCluster()`) , the command that undoes registration is `registerDoSEQ()`. Don't forget to turn off your clusters.
Problem
How do I get parallelizaton of code to work in r in Windows? Include a simple example. Posting this self-answered question because this was rather unpleasant to get working. You'll find package parallel does NOT work on its own, but package snow works very well.