Storing tic toc values in R

Question

I'm looking for a way to store running times in a variable in R. In MATLAB one can do something along the lines:

tic;
...
x=toc;

and then the running time is stored in the variable x. I have tried doing the same thing with the tic() toc() function in R coming from the MATLAB-package without success. Furthermore I can't see how this can be done using the system.time() function of R neither. Any help here is much appreciated.

Duplicated question: http://stackoverflow.com/questions/1716012/stopwatch-function-in-r — Vincent Zoonekynd, Jun 05 '12 at 08:29
@StefanHansen: you store it like you store any other variable value... `<-`. — Joshua Ulrich, Jun 05 '12 at 10:22

score 15 · Answer 1 · answered Jun 05 '12 at 10:28

15

More similar to tic and toc and sometimes handier e.g. for status messages in loops:

start <- Sys.time ()
do.something ()
Sys.time () - start

answered Jun 05 '12 at 10:28

cbeleites unhappy with SX

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digEmAll · Accepted Answer · 2012-06-05T09:07:00.037

14

Use the built-in system.time function:

tm1 <- system.time(
{
  #your code here
})

or, alternatively the benchmark function from rbenchmark package:

tm2 <- benchmark(
{
  #your code here
}, replications=1)

edited Jun 05 '12 at 09:07

answered Jun 05 '12 at 08:06

digEmAll

56,430
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Oh, it was that simple. Thanks :) – Stefan Hansen Jun 05 '12 at 08:10
I prefer using `system.time` function because: 1. It encapsulates the code that I want to time; 2. In-built function, loading libraries like `tictoc`, `rbenchmark` unnecessary. – Sumax Oct 15 '19 at 07:45

score 5 · Answer 3 · edited Apr 28 '20 at 06:25

5

Or you can do as it is described in the 'tictoc' package.

tic("timer")
1+1
toc(log = TRUE, quiet = TRUE)
log.txt <- tic.log(format = TRUE)
tic.clearlog()

your output is then stored in log.txt. You can unlist(log.txt) and analyse it as a string if you only want the time in seconds.

Cheers,

edited Apr 28 '20 at 06:25

micstr

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answered Jun 15 '17 at 11:44

AleRuete

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Sergei Izrailev · Answer 4 · 2017-12-24T06:23:26.327

The tictoc package implements this exact functionality, so the timing of sequential or nested timings is stored in a list and for subsequent analysis.

For example, to time each iteration of a loop and analyze the results later, use the log functionality.

library(tictoc)
tic.clearlog()
for (x in 1:10) {
    # passing x to tic() makes it a label at time of the matching toc() call.
    tic(x)
    Sys.sleep(1)
    # When log = TRUE, toc() pushes the measured timing to a list
    # quiet = TRUE prevents from printing the timing
    toc(log = TRUE, quiet = TRUE)
}

Fetch the results of toc() as formatted text for printing.

log.txt <- tic.log(format = TRUE)

Extract the list containing measurements in raw format.

log.lst <- tic.log(format = FALSE)

Since the data is already extracted, clear the tictoc log.

tic.clearlog()

Convert the list elements to timings. Each element of the list has a start (tic) and end (toc) timestamp.

timings <- unlist(lapply(log.lst, function(x) x$toc - x$tic))

Compute the average loop time.

mean(timings)
# [1] 1.001

Print the text output - note that the prefixes are the values of x.

writeLines(unlist(log.txt))
# 1: 1.002 sec elapsed
# 2: 1 sec elapsed
# 3: 1.002 sec elapsed
# 4: 1.001 sec elapsed
# 5: 1.001 sec elapsed
# 6: 1.001 sec elapsed
# 7: 1.001 sec elapsed
# 8: 1.001 sec elapsed
# 9: 1.001 sec elapsed
# 10: 1 sec elapsed

An imho more elegant conversion of the results into a dataframe could be done using `purrr` with `log.st %>% map_df(~as_data_frame(.x)) %>% mutate(elapsed=toc-tic)` — Holger Brandl, Apr 03 '20 at 06:01
Thanks, @HolgerBrandl. A minor correction in the code: `library(tidyverse); log.lst %>% map_df(~as.data.frame(.x)) %>% mutate(elapsed=toc-tic)` — Sergei Izrailev, Apr 06 '20 at 02:54

Storing tic toc values in R

4 Answers4