Stopwatch function in R

Question

Is there an R timer or stopwatch function similar to MATLAB\'s tic/toc?

Answer 1

There is a MATLAB emulation package matlab on CRAN. It has implementations of tic and toc (but they look very similar to the functions in Richie Cottons answer; "elapsed" is used instead of "user.self" in proc.time())

> tic
function (gcFirst = FALSE) 
{
    if (gcFirst == TRUE) {
        gc(verbose = FALSE)
    }
    assign("savedTime", proc.time()[3], envir = .MatlabNamespaceEnv)
    invisible()
}
<environment: namespace:matlab>
> toc
function (echo = TRUE) 
{
    prevTime <- get("savedTime", envir = .MatlabNamespaceEnv)
    diffTimeSecs <- proc.time()[3] - prevTime
    if (echo) {
        cat(sprintf("elapsed time is %f seconds", diffTimeSecs), 
            "\n")
        return(invisible())
    }
    else {
        return(diffTimeSecs)
    }
}
<environment: namespace:matlab>

Answer 2

No, but here is a one line solution.

time.it<-function(f) { a<-proc.time(); out<-f(); print(proc.time()-a); out }

And an example for usage:

result<-time.it(function(){ A<-matrix(runif(5000^2),nrow=5000); b<-runif(5000); solve(A,b) } )
user  system elapsed 
12.788  12.268   8.623 

Otherwise, microbenchmark is my favorite in terms of packages.

Answer 3

install.packages("tictoc")
library(tictoc)
# Timing nested code. 
# The string provided in the call to tic() becomes a prefix to the output of toc()
tic("outer")
    Sys.sleep(1)
    tic("middle")
        Sys.sleep(2)
        tic("inner")
            Sys.sleep(3)
        toc() # inner
# inner: 3.004 sec elapsed
    toc() # middle
# middle: 5.008 sec elapsed
toc() # outer
# outer: 6.016 sec elapsed

The tictoc package implements the functionality described by previous answers - thank you for inspiration! The package also adds nested timing, collecting the timings in user-defined variables, custom messages and callbacks.

Answer 4

There are plenty of profiling tools in R, as Dirk mentioned. If you want the simplicity of tic/toc, then you can do it in R too.

EDIT: I've cannibalised the garbage collection functionality from the MATLAB package, and tic now lets you choose whether you are interested in total elapsed time or just the user time.

tic <- function(gcFirst = TRUE, type=c("elapsed", "user.self", "sys.self"))
{
   type <- match.arg(type)
   assign(".type", type, envir=baseenv())
   if(gcFirst) gc(FALSE)
   tic <- proc.time()[type]         
   assign(".tic", tic, envir=baseenv())
   invisible(tic)
}

toc <- function()
{
   type <- get(".type", envir=baseenv())
   toc <- proc.time()[type]
   tic <- get(".tic", envir=baseenv())
   print(toc - tic)
   invisible(toc)
}

Usage is, e.g., tic(); invisible(qr(matrix(runif(1e6), nrow=1e3))); toc()

Answer 5

Just for completeness: you can actually 'simulate' tic and toc in R, so that you can write

tic
## do something
toc

without parentheses. The trick is to abuse the print function, as demonstrated in Fun: tic and toc in R:

tic <- 1
class(tic) <- "tic"

toc <- 1
class(toc) <- "toc"

print.tic <- function(x, ...) {
    if (!exists("proc.time"))
        stop("cannot measure time")
    gc(FALSE)
    assign(".temp.tictime", proc.time(), envir = .GlobalEnv)
}

print.toc <- function(x,...) {
    if (!exists(".temp.tictime", envir = .GlobalEnv))
        stop("did you tic?")
    time <- get(".temp.tictime", envir = .GlobalEnv)
    rm(".temp.tictime", envir = .GlobalEnv)
    print(res <- structure(proc.time() - time,
                           class = "proc_time"), ...)
    invisible(res)
}

So typing

tic
Sys.sleep(2)
toc

should results in something like this:

   user  system elapsed 
  0.000   0.000   2.002 

As I said, it's a trick; system.time, Rprof and packages such as rbenchmark are the way to measure computing time in R.

Answer 6

A very simple equivalence with tic and toc that you could have:

tic=proc.time()[3]

...code...

toc=proc.time()[3] - tic

Where the [3] is because we are interested in the third element in the vector returned by proc.time(), which is elapsed time.