[R] possible bug in function 'mclapply' of package parallel

[Michael Weylandt]

Mailing list ate the attachment. 

Can you send it plain text (if short) or post it somewhere online?

Michael

On Dec 13, 2012, at 1:54 AM, Asis Hallab <asis.hallab at gmail.com> wrote:

> Dear parallel users and developers,
> 
> I might have encountered a bug in the function 'mclapply' of package
> 'parallel'. I construct a matrix using the same input data and code with a
> single difference: Once I use mclapply and the other time lapply.
> 
> Shockingly the result is NOT the same.
> 
> To evaluate please unpack the attached archive and execute
> Rscript mclapply_test.R
> 
> I put the two simple functions I wrote inside the R script and the
> serialized input matrix.
> My function is once executed using mclapply and the other time lapply
> internally. - There's an argument lapply.funk, one can set to mclapply.
> 
> The results are checked for identity with a striking FALSE.
> 
> Any hints on my misuse and or misunderstanding of mclapply or verification
> of a true bug will be much appreciated.
> 
> Kind regards!
> ______________________________________________
> R-help at 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.