system.time {base}

R Documentation

CPU Time Used

Description

system.time calls the builtin proc.time, evaluates expr, and the calls proc.time once more, returning the difference to between the proc.time calls.

The values returned by the proc.time are (currently) those returned by the C library function times(3v).

Usage

system.time(expr)

Arguments

expr	Valid R expression to be “timed”

Value

A numeric vector of length 5 containing the cpu, user, total, subproc1, subproc2 times.

See Also

proc.time, time which is for time series.

Examples

system.time(for(i in 1:50) mad(runif(500)))
exT <- function(n = 100) {
  # Purpose: Test if system.time works ok;   n: loop size
  system.time(for(i in 1:n) x <- mean(rt(1000, df=4)))
}
#-- Try to interrupt one of the following (using Ctrl-C):
exT()                 #- `1.4' on -O-optimized Ultra1
system.time(exT())    #~ +/- same

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