On Thu, 17-Oct-2013 at 02:21PM -0300, Luís Paulo F. Garcia wrote: |> I work very mutch with the packages RWeka and multicore. If you try to run |> J48 or any tree of RWeka with multicore we hava some errors. |> |> Example I: |> |> library(RWeka); |> library(multicore); |> |> mclapply(1:100, function(i) { |> J48(Species ~., iris); |> }); |> |> |> Output: "Error in .jcall(o, \"Ljava/lang/Class;\", \"getClass\") : \n |> java.lang.ClassFormatError: Incompatible magic value 1347093252 in class |> file java/lang/ProcessEnvironment$StringEnvironment\n" |> |> |> Example II: |> |> library(multicore); |> |> mclapply(1:100, function(i) { |> RWeka::J48(Species ~., iris); |> }); |> |> Output: Erro em .jcall(x$classifier, "S", "toString") : |> RcallMethod: attempt to call a method of a NULL object. |> |> |> Do you know some way to work with parallel processing and RWeka? I tried |> MPI and SNOW without success.
Not much help, but I too have not been able to get parallelling RWeka to work. OTOH, what RWeka can do is very fast compared with, say, gbm (which does work well with mclapply). I suspect that it has something to do with how Java is set up, but I know nothing about setting up Java. |> |> R version 3.0.2 (2013-09-25) -- "Frisbee Sailing" |> Ubuntu 12.04 x64 |> |> |> -- |> Lu?s Paulo Faina Garcia |> Engenheiro de Computa??o - Universidade de S?o Paulo |> S?o Carlos - SP - Brasil |> |> [[alternative HTML version deleted]] |> |> ______________________________________________ |> R-help@r-project.org mailing list |> https://stat.ethz.ch/mailman/listinfo/r-help |> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html |> and provide commented, minimal, self-contained, reproducible code. -- ~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~. ___ Patrick Connolly {~._.~} Great minds discuss ideas _( Y )_ Average minds discuss events (:_~*~_:) Small minds discuss people (_)-(_) ..... Eleanor Roosevelt ~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.