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timing a function

10 messages · pdb, mohamed.lajnef at inserm.fr, Joris Meys +4 more

Original
mohamed.lajnef at inserm.fr
# 
Hi,

? proc.time() for more help

regards
Ml

pdb <philb at philbrierley.com> a ?crit?:
12 days later
Peter Ehlers
#
On 2010-05-17 10:49, Gustave Lefou wrote:
No. You should be careful in your use of '=' which is only allowed at 
top level.

Try
  system.time(y <- f(x))

and see ?"=".

  -Peter Ehlers
Barry Rowlingson
#
On Mon, May 17, 2010 at 6:24 PM, Peter Ehlers <ehlers at ucalgary.ca> wrote:

            

      
      
      
    

        
Ah ha. That explains the curly brackets I saw in a posting with
system.time on stack overflow just now:

 system.time({y=f(x)})

 works as expected since the {} pair make a new code block. Also you
can then time more than one statement:

 system.time({y=f(x);z=g(y)})

 - gives the total time for f(x) and g(y).

Barry

  
  


  


      

    

    

      
      

        
      

    

    

      
      

        


  

        

      Alexander Shenkin
    

    

      
      #
    

  


  

      
You could also put the call to system.time inside the function itself:

f = function(x) {
    system.time({
        ... #function's code
        ret_val = ...
    }); flush.console();
    return ret_val;
}

i s'pose you'd miss out on the time taken to jump to the function code,
return the value, etc, but for functions that are heavy at all, that
wouldn't trip you up.

allie

        
On 5/17/2010 2:06 PM, Barry Rowlingson wrote: