# timed

##### Record the Computation Time

Saves the result of a calculation as an object of class `"timed"`

which includes information about the time taken to compute the result.
The computation time is printed when the object is printed.

##### Usage

`timed(x, ..., starttime = NULL, timetaken = NULL)`

##### Arguments

- x
- An expression to be evaluated, or an object that has already been evaluated.
- starttime
- The time at which the computation is defined to have started.
The default is the current time.
Ignored if
`timetaken`

is given. - timetaken
- The length of time taken to perform the computation.
The default is the time taken to evaluate
`x`

. - ...
- Ignored.

##### Details

This is a simple mechanism for recording how long it takes to
perform complicated calculations (usually for the purposes of
reporting in a publication).
If `x`

is an expression to be evaluated, `timed(x)`

evaluates the expression and measures the
time taken to evaluate it.
The result is saved as an object of the class
`"timed"`

. Printing this object displays the computation time.

If `x`

is an object which has already been computed,
then the time taken to compute the object can be specified either directly
by the argument `timetaken`

, or indirectly by the argument
`starttime`

.

`timetaken`

is the duration of time taken to perform the computation. It should be the difference of two clock times returned by`proc.time`

. Typically the user sets`begin <- proc.time()`

before commencing the calculations, then`end <- proc.time()`

after completing the calculations, and then sets`timetaken <- end - begin`

.`starttime`

is the clock time at which the computation started. It should be a value that was returned by`proc.time`

at some earlier time when the calculations commenced. When`timed`

is called, the computation time will be taken as the difference between the current clock time and`starttime`

. Typically the user sets`begin <- proc.time()`

before commencing the calculations, and when the calculations are completed, the user calls`result <- timed(result, starttime=begin)`

.

`x`

belongs to other S3 classes,
then the result of `timed(x, ...)`

also inherits these classes,
and printing the object will display the appropriate information for these
classes as well.
##### Value

- An object inheriting the class
`"timed"`

.

##### Examples

`timed(envelope(cells, nsim=19))`

*Documentation reproduced from package spatstat, version 1.41-1, License: GPL (>= 2)*