Running Time of R

Description

proc.time determines how much time (in seconds) the currently running R process already consumed.

Usage

proc.time()

Value

A numeric vector of length 5, containing the user, system, and total elapsed times for the currently running R process, and the cumulative sum of user and system times of any child processes spawned by it.
The resolution of the times will be system-specific; it is common for them to be recorded to of the order of 1/100 second, and elapsed time is rounded to the nearest 1/100.
It is most useful for “timing” the evaluation of R expressions, which can be done conveniently with system.time.

Note

It is possible to compile R without support for proc.time, when the function will throw an error.

References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

See Also

system.time for timing a valid R expression, gc.time for how much of the time was spent in garbage collection.

Examples

## Not run: 
## a way to time an R expression: system.time is preferred
ptm <- proc.time()
for (i in 1:50) mad(runif(500))
proc.time() - ptm
## End(Not run)