[R] Time it takes to run a code

[Boris Steipe]

It may be useful for you to estimate the time complexity of your function: try it with smaller input that takes short and noticeable time, see whether the time increases linearly, quadratically, or exponentially with the number of elements you process, then  extrapolate to your full data set.


To see what your function is doing, you could 
- add a print statement that tells you the progress every 1000 or 10,000 items or so...
- add a progress bar
     https://stat.ethz.ch/R-manual/R-patched/library/utils/html/txtProgressBar.html
- install and use the pbapply package
    https://cran.r-project.org/web/packages/pbapply/pbapply.pdf


You are right to make sure you are getting some feedback, it is easy to make a mistake in function logic that will cause a function to fail to terminate.


B.



On Oct 25, 2015, at 5:05 PM, Maram SAlem <marammagdysalem at gmail.com> wrote:

> Hi All,
> 
> I'm using a function, say func, and I want to apply it to all the rows of a
> certain matrix. The problem is that my code kept on running for more than
> two days without giving any output. I've made some modifications.But is
> there a way to know the time needed to execute my code and reach an ouput
> but before running the code and not after it is run? I've tried Sys.time()
> and system.time(), but still the console freezed for so long and I didn't
> reach anything.
> 
> Any suggestions are much appreciated.
> Thanks in advance.
> 
> Maram Salem
> 
> 	[[alternative HTML version deleted]]
> 
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