Stopwatch function in R

Question

Is there an R timer or stopwatch function similar to MATLAB\'s tic/toc?

Answer 1

install.packages("tictoc")
library(tictoc)
# Timing nested code. 
# The string provided in the call to tic() becomes a prefix to the output of toc()
tic("outer")
    Sys.sleep(1)
    tic("middle")
        Sys.sleep(2)
        tic("inner")
            Sys.sleep(3)
        toc() # inner
# inner: 3.004 sec elapsed
    toc() # middle
# middle: 5.008 sec elapsed
toc() # outer
# outer: 6.016 sec elapsed

The tictoc package implements the functionality described by previous answers - thank you for inspiration! The package also adds nested timing, collecting the timings in user-defined variables, custom messages and callbacks.