Yep. I got similar results. Some person recommands to use some non-trival
examples.  My concern is that the package doesn't give the correct answer
even for the non-trival example, how can you expect it to work for other
examples? See one of my example:

> mclapply(1:10, function(x)rnorm(x), mc.cores=1)
[[1]]
[1] -0.3462702
[[2]]
[1] -2.02105262 -0.09585892
[[3]]
[1]  1.77221975 -0.46601980 -0.07315387
[[4]]
[1] -2.1283152 -0.6079173  0.4305617  0.3908323
[[5]]
[1] -1.1565899  2.5569418  2.1897070  1.0436908 -0.5969151
[[6]]
[1]  0.9828604 -0.1479499 -0.1284607 -0.3347436  1.8018194 -1.4417220
[[7]]
[1]  0.55425627 -0.09030843 -0.60091740  0.12777185 -0.13998607  0.35154851
[7] -0.04631663
[[8]]
[1] -0.35164946  0.97417980 -1.49269589 -0.18409462  0.06105646  0.26404434
[7] -0.18976067 -1.14565065
[[9]]
[1]  0.22496664  1.06111320  2.01179778 -0.27569373 -0.42400996 -0.05679749
[7]  0.30982861  1.52450703 -0.21109130
[[10]]
 [1] -1.3539043 -1.3596462  0.5039675 -1.1326639  0.2802417 -0.1049306
 [7] -0.3243349  0.4130826  0.9384500  1.3505106
> mclapply(1:10, function(x)rnorm(x), mc.cores=2)
[[1]]
[1] -0.6564236
[[2]]
[1]  0.2981595 -0.9662663 -0.1586778
[[3]]
[1]  0.20283018  1.91891067 -0.03065513 -1.25895660 -1.43237050
[[4]]
[1] -0.97452271  1.95556392 -0.01407120 -1.45767782  0.83977490  1.20149231
[7] -0.65395606
[[5]]
[1] -0.36855293  0.57518030 -1.52608826 -1.01052287  0.07453356 -1.47265355
[7] -0.05276850 -0.97598956 -0.43125376
> mclapply(1:10, function(x)rnorm(x), mc.cores=2)
list()
> mclapply(1:10, function(x)rnorm(x), mc.cores=2)
list()
> mclapply(1:10, function(x)rnorm(x), mc.cores=2)
[[1]]
NULL
[[2]]
[1]  0.4338477 -0.2756795
[[3]]
NULL
[[4]]
[1] -0.08792539 -0.21166520 -0.07175587 -1.44629997
[[5]]
NULL
[[6]]
[1] -0.11538155  1.47215456  0.12418766 -0.09469826  1.24639136 -2.08412950
[[7]]
NULL
[[8]]
[1]  0.59884313 -0.69780323 -1.50954506 -0.04156023  0.20434899 -0.59812782
[7]  0.88432575 -0.41230545
[[9]]
NULL
[[10]]
 [1] -2.2547262 -0.2821773  0.8624573  0.4983850  0.5977264  1.8459354
 [7] -0.8028298  1.0817651 -2.0418556 -0.2725846
>
It even fails to generate the correct number of random numbers. How can I
use this package to do simulations?

On Tue, Aug 11, 2009 at 10:18 PM, <davidr@rhotrading.com> wrote:

> I understand that the support for Windows is experimental,
> so I thought I'd just try it out.
> Maybe I don't understand some things.
> Can someone explain what's going on here?
> Is this as expected, and what am I doing wrong?
> (I am on Windows XP SP2, and have 8 cores. SessionInfo below.)
>
> > install.packages('multicore',,'http://www.rforge.net/')
> trying URL
> 'http://www.rforge.net/bin/windows/contrib/2.9/multicore_0.1-4.zip'
> Content type 'application/zip' length 90538 bytes (88 Kb)
> opened URL
> downloaded 88 Kb
>
> package 'multicore' successfully unpacked and MD5 sums checked
>
> The downloaded packages are in
>        C:\Documents and Settings\davidr\Local
> Settings\Temp\Rtmpv52Ozb\downloaded_packages
> updating HTML package descriptions
> > library(multicore)
> > mclapply(1:10, sqrt, mc.cores=1)
> [[1]]
> [1] 1
> [[2]]
> [1] 1.414214
> [[3]]
> [1] 1.732051
> [[4]]
> [1] 2
> [[5]]
> [1] 2.236068
> [[6]]
> [1] 2.449490
> [[7]]
> [1] 2.645751
> [[8]]
> [1] 2.828427
> [[9]]
> [1] 3
> [[10]]
> [1] 3.162278
>
> > mclapply(1:10, sqrt, mc.cores=2)
> [[1]]
> [1] 1
> [[2]]
> [1] 1.732051
> [[3]]
> [1] 2.236068
> [[4]]
> [1] 2.645751
> [[5]]
> [1] 3
>
> > sessionInfo()
> R version 2.9.1 (2009-06-26)
> i386-pc-mingw32
>
> locale:
> LC_COLLATE=English_United States.1252;LC_CTYPE=English_United
> States.1252;LC_MONETARY=English_United
> States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252
>
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
>
>
> other attached packages:
> [1] multicore_0.1-4
>
> loaded via a namespace (and not attached):
> [1] tools_2.9.1
>
> Thanks for any insight,
> David L. Reiner
> Rho Trading Securities, LLC
>
>
>
> This e-mail and any materials attached hereto, including, without
> limitation, all content hereof and thereof (collectively, "Rho Content") are
> confidential and proprietary to Rho Trading Securities, LLC ("Rho") and/or
> its affiliates, and are protected by intellectual property laws.  Without
> the prior written consent of Rho, the Rho Content may not (i) be disclosed
> to any third party or (ii) be reproduced or otherwise used by anyone other
> than current employees of Rho or its affiliates, on behalf of Rho or its
> affiliates.
>
> THE RHO CONTENT IS PROVIDED AS IS, WITHOUT REPRESENTATIONS OR WARRANTIES OF
> ANY KIND.  TO THE MAXIMUM EXTENT PERMISSIBLE UNDER APPLICABLE LAW, RHO
> HEREBY DISCLAIMS ANY AND ALL WARRANTIES, EXPRESS AND IMPLIED, RELATING TO
> THE RHO CONTENT, AND NEITHER RHO NOR ANY OF ITS AFFILIATES SHALL IN ANY
> EVENT BE LIABLE FOR ANY DAMAGES OF ANY NATURE WHATSOEVER, INCLUDING, BUT NOT
> LIMITED TO, DIRECT, INDIRECT, CONSEQUENTIAL, SPECIAL AND PUNITIVE DAMAGES,
> LOSS OF PROFITS AND TRADING LOSSES, RESULTING FROM ANY PERSON'S USE OR
> RELIANCE UPON, OR INABILITY TO USE, ANY RHO CONTENT, EVEN IF RHO IS ADVISED
> OF THE POSSIBILITY OF SUCH DAMAGES OR IF SUCH DAMAGES WERE FORESEEABLE.
>
> _______________________________________________
> R-sig-hpc mailing list
> R-sig-hpc@r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-hpc
>

	[[alternative HTML version deleted]]

