[R] Compilation of R code

[Spencer Graves]

      R is basically an interpreted language.  To my knowledge, the 
standard approach to improving speed starts by finding which steps take 
the most time.  This can be done using "proc.time" and / or 
"system.time" (preceded by "gc" to clean things up so the timing is more 
stable). 

      Once you've determined which loop or function call consumes the 
most time, you then need to decide what to do about it.  R is 
vectorized, so if you use loops like in Fortran or C, you might be able 
to replace complicated pieces of code with one or only a very few 
commands.  This list has considered many questions about speed, so once 
you know which steps are taking the most time, you can search the 
archives as described in the posting guide, 
"http://www.R-project.org/posting-guide.html".  If that does not solve 
the problem, you can translate a function into a compiled language like 
C.  See help.start() -> "Writing R Extensions" -> "System and foreign 
language interfaces". 

      hope this helps. 
      spencer graves

Depire Alexandre wrote:

>Hello,
>I'm a newbie on this list.
>I have a R code but its execution take a very long time.
>Is it possible to compile it (in C for example) to decrease the execution 
>time ?
>
>  
>