R: Record the Computation Time

timed {spatstat} | R Documentation

## Record the Computation Time

### Description

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)`.

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"`.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk.

### See Also

`timeTaken` to extract the time taken.

### Examples

      timed(clarkevans(cells))

      timed(Kest(cells))

      answer <- timed(42, timetaken=4.1e17)
      answer

[Package spatstat version 1.63-3 Index]