[R] Dramatic slowdown of R 2.7.2?

[Peter Dalgaard]

Marek Wielgosz wrote:
> Dear R users/developers,
>
> simple comparison of code execution time of R 2.7.1 and R 2.7.2 shows 
> a dramatic slowdown of the newer version. Rprof() identifies .Call 
> function as a main cause (see the code below). What happened with R 
> 2.7.2? 
I don't see much of a difference, running on Linux or under Wine on 
Linux though, and scaled down to 3*10^2. With a large matrix inversion 
as the workhorse, it is hardly surprising that .Call eats most of the 
time, but one could easily get the idea that you aren't picking up the 
same BLAS in both cases(?)

> Kind regards
> Marek Wielgosz
> Bayes Consulting
>
> ######### Probably useful info ###############
> ### CPU: Core2Duo T 7300, 2 GB RAM
> ### WIN XP
> ### both standard Rblass.dll files
> ### both pre-compiled binary versions of R
>
> ######### R 2.7.1 ############################
> #R version 2.7.1 (2008-06-23)
> #i386-pc-mingw32
> #
> #locale:
> #LC_COLLATE=Polish_Poland.1250;LC_CTYPE=Polish_Poland.1250;LC_MONETARY=Polish_Poland.1250;LC_NUMERIC=C;LC_TIME=Polish_Poland.1250 
>
> #
> #attached base packages:
> #[1] stats     graphics  grDevices utils     datasets  methods   base
>
> ######### R 2.7.2 ############################
> #R version 2.7.2 (2008-08-25)
> #i386-pc-mingw32
> #
> #locale:
> #LC_COLLATE=Polish_Poland.1250;LC_CTYPE=Polish_Poland.1250;LC_MONETARY=Polish_Poland.1250;LC_NUMERIC=C;LC_TIME=Polish_Poland.1250 
>
> #
> #attached base packages:
> #[1] stats     graphics  grDevices utils     datasets  methods   base  
> ################################################
>
> The following code has been executed (with both R 2.7.1 and R 2.7.2):
>
> Rprof(tmp <- tempfile())
> sample_size=10
> f1=function(k) {solve(matrix(rnorm(4*k^2),2*k,2*k))}
> out=vector(,sample_size)
> for (i in 1:sample_size) {out[i]=system.time(f1(10^3))[[3]]}
> summaryRprof(tmp)
> out_summary=matrix(,1,6,dimnames=list("value",c("dim","min","mean","med","sd","max"))) 
>
> out_summary[1,1]=sample_size
> out_summary[1,2]=min(out)
> out_summary[1,3]=mean(out)
> out_summary[1,4]=median(out)
> out_summary[1,5]=sd(out)
> out_summary[1,6]=max(out)
> out_summary
>
> ______________________________________________
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> PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.


-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark      Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)              FAX: (+45) 35327907