Parallel problem and a fix

By default, R only uses one of the 12 cores in my workstation. According to this post, the easiest solution is to put "system(sprintf("taskset -p 0xffffffff %d", Sys.getpid()))" in my .Rprofile.

Even better, one can simply put a line "mcaffinity(1:12)" everytime the "parallel" package is loaded.