[R] Two Questions on R (call by reference and pre-compilation)
ruihong.huang at wiwi.hu-berlin.de
Tue May 4 23:05:17 CEST 2010
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.
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