R help - Dec 2012 - possible bug in function 'mclapply' of package parallel

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!

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!
> ______________________________________________
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