Rprof {utils} | R Documentation

## Enable Profiling of R's Execution

### Description

Enable or disable profiling of the execution of R expressions.

### Usage

    Rprof(filename = "Rprof.out", append = FALSE, interval = 0.02)

### Arguments

`filename` | The file to be used for recording the profiling results. Set to `NULL` or `""` to disable profiling.
`append` | logical: should the file be over-written or appended to?
`interval` | real: time interval between samples.

### Details

Enabling profiling automatically disables any existing profiling to another or the same file.

Profiling works by writing out the call stack every `interval` seconds, to the file specified. Either the `summaryRprof` function or the Perl script `R CMD Rprof` can be used to process the output file to produce a summary of the usage; use `R CMD Rprof --help` for usage information.

Exactly what the time interval measures is subtle: it is time that the R process is running and executing an R command. It is not however just CPU time, for if `readline()` is waiting for input, that counts (on Windows, but not on Unix).

Note that the timing interval cannot be too small, for the time spent in each profiling step is added to the interval. What is feasible is machine-dependent, but 10ms seems as small as advisable on a 1GHz machine.

### Note

Using `R CMD Rprof` needs Windows Perl to be installed.

### See Also

The chapter on “Tidying and profiling R code” in “Writing R Extensions” (see the ‘`doc/manual`’ subdirectory of the R source tree).

`summaryRprof`

### Examples

    ## Not run:
    Rprof()
    ## some code to be profiled
    Rprof(NULL)
    ## some code NOT to be profiled
    Rprof(append=TRUE)
    ## some code to be profiled
    Rprof(NULL)
    ...
    ## Now post-process the output as described in Details
    ## End(Not run)

[Package utils version 2.3.1 Index]