0) Profiling your code
GUIProfiler Package
Profiling Example
library(GUIProfiler) profile.func <- function() { apply.function <- function(data) { summary(data) min(data); max(data) range(data) mean(data); median(data) sd(data); mad(data) IQR(data) quantile(data) quantile(data, c(1, 3)/4) } #start time strt<-Sys.time() data.list <- replicate(10, rnorm(500000), simplify=FALSE) lapply(data.list, apply.function) # time taken print(Sys.time()-strt) } RRprofStart() profile.func() RRprofStop() RRprofReport()