[R] snow: cluster initialization

[Jon Olav Skoien]

I also wanted to add the result from my Windows machine (R 3.0.0) to the 
answer below:

 > ncore = system('nproc')
 > ncore
[1] 127
# My machine was not happy about starting a cluster with 127 nodes though.

Best wishes,
Jon

On 18-Apr-13 15:13, Jon Olav Skoien wrote:
> I dont think this has anything to do with the snow package, you should 
> rather start by checking what is the output of system('nproc') is on 
> your computer, and also whether it is possible to assign this to a 
> variable. I tried on a redhat linux (R 2.15.0) server:
>
> > ncore = system('nproc')
> 16
> > ncore
> [1] 0
> # the result is printed, not returned
>
>
> Best wishes,
> Jon
>
> On 18-Apr-13 10:52, Kaiyin Zhong (Victor Chung) wrote:
>> Dear all,
>>
>> I found a strange thing with the snow package.
>>
>> This will work:
>> y = matrix(1:4, 2)
>> cl = makeCluster(rep('localhost', 8), type='SOCK')
>> parMM(cl, y, y)
>>
>> This will not:
>>
>> y = matrix(1:4, 2)
>> ncore = system('nproc')
>> parMM(cl, y, y)
>> Error in cut.default(i, breaks) : invalid number of intervals
>>
>> I also tried:
>> cl = makeCluster(rep('localhost', ncore), type='SOCK')
>> cl = makeCluster(rep('localhost', as.integer(ncore)), type='SOCK')
>>
>> no luck.
>>
>>
>> Could anyone please help? Thanks!
>>
>>
>>
>>
>>
>>
>> Best regards,
>>
>> Kaiyin ZHONG
>> ------------------------------
>> FMB, Erasmus MC
>> k.zhong at erasmusmc.nl
>> kindlychung at gmail.com
>>
>>     [[alternative HTML version deleted]]
>>
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>
>


-- 
Jon Olav Skøien
Joint Research Centre - European Commission
Institute for Environment and Sustainability (IES)
Land Resource Management Unit

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jon.skoien at jrc.ec.europa.eu
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