Sometimes a minor change to your R code can make a big difference in processing time. Here is an example showing that if you’re don’t care about the names attribute when unlist():ing a list, specifying argument use.names = FALSE can speed up the processing lots!
> x <- split(sample(1000, size = 1e6, rep = TRUE), rep(1:1e5, times = 10)) > t1 <- system.time(y1 <- unlist(x)) > t2 <- system.time(y2 <- unlist(x, use.