proc.time {base} | R Documentation |
proc.time
determines how much real and CPU time (in seconds)
the currently running R process has already taken.
proc.time()
proc.time
returns five elements for backwards compatibility,
but its print
method prints a named vector of
length 3. The first two entries are the total user and system CPU
times of the current R process and any child processes on which it
has waited, and the third entry is the ‘real’ elapsed time
since the process was started.
An object of class "proc_time"
which is 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 on which it has
waited. (The print
method combines the child times with those
of the main process.)
The definition of ‘user’ and ‘system’ times is from your
OS. Typically it is something like
The ‘user time’ is the CPU time charged for the execution
of user instructions of the calling process. The ‘system time’
is the CPU time charged for execution by the system on behalf of the
calling process.
The resolution of the times will be system-specific
and are typically available to 10ms on Windows.
This is a primitive function.
Times of child processes are not available and will always be given as
NA
.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
system.time
for timing a valid R expression,
gc.time
for how much of the time was spent in garbage
collection.
## Not run: ## a way to time an R expression: system.time is preferred ptm <- proc.time() for (i in 1:50) mad(stats::runif(500)) proc.time() - ptm ## End(Not run)