# 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.

- Keywords
- utilities

##### 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)`

.

If the result of evaluating `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"`

.

##### See Also

`timeTaken`

to extract the time taken.

##### Examples

```
# NOT RUN {
timed(clarkevans(cells))
timed(Kest(cells))
answer <- timed(42, timetaken=4.1e17)
answer
# }
```

*Documentation reproduced from package spatstat, version 1.55-1, License: GPL (>= 2)*