[R] parsing speed

Duncan Murdoch murdoch at stats.uwo.ca
Tue May 17 00:09:14 CEST 2005


Federico Calboli wrote:
> Hi everyone,
> 
> I have a question on parsing speed.
> 
> I have two functions:
> 
> F1
> F2
> 
> As things are now, F2 calls F1 internally:
> 
> F2 =  function(x){
> if (something == 1){
> y = F1(x)
> }
> if (something ==2){
> do whatever
> }
> }
> 
> *Assuming there could be some difference*, is is faster to use the code
> as written above or should I actually write the statements of F1 to make
> the parsing faster? 

The parsing only happens once when you define the functions, and is 
(almost always) a negligible part of total execution time.  I think 
you're really worried about execution time.  You'll probably get more 
execution time with a separate function because function calls take time.

However, my guess is that putting F1 inline won't make enough difference 
to notice.

Duncan




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