On 8/28/2008 3:25 PM, [EMAIL PROTECTED] wrote:
Full_Name: R User Version: 2.7.2 (default binary) OS: Windows XP SP2 Submission from: (NULL) (83.25.29.163)Hello! I have conducted following experiment running simple R script: for (i in 1:10000) { a<-0 for (j in 1:1000) a<-c(a,j) } profiled R.dll using Intel Vtune and obtained following results!!! Func. Name Clocticks locale2charset 46,58% R_RunWeakRefFinalizer 20,85% Rf_eval 8,77%Rf_eval takes only about 9% of CPU time, a huge overhead on checking locale character set!!! It seems that is the problem with family of functions: c(), rbind(), cbind()
I don't have Vtune, so I don't know that its clock counts are reliable. Could you please identify where the calls to locale2charset are coming from? I don't see anything obvious in the source that would explain this, so I suspect Vtune is misreporting.
If I were to guess, I would say your loop would be spending most of its time in memory management functions, since you allocate and reallocate "a" so many times. Since those aren't even mentioned by Vtune, I think it is confused.
Duncan Murdoch ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
