[R] Two Questions on R (call by reference and pre-compilation)

Ruihong Huang ruihong.huang at wiwi.hu-berlin.de
Tue May 4 23:05:17 CEST 2010


Hi All,

I have two questions on R. Could you please explain them to me? Thank you!

1) When call a function, R typically copys the values to formal 
arguments (call by value). This is very cost, if I would like to pass a 
huge data set to a function. Is there any situations that R doesn't copy 
the data, besides pass data in an environment object.

2) Does R pre-compile the object function to binary when running 
"optim"? I experienced the R "optim" is much slower than the MATLAB 
"fmincon" function. I don't know MATLAB has done any pre-compilation on 
the script for object function or not. But perhaps, we can increase R 
performance by some sort of pre-compilation during running time.


Thanks in advance.


Best Regards,
Ruihong


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