[R] Multi-threads in R

[Fabrice Tourre]

I think multicore is one of answer if you can write your function in to lapply.

On Mon, Jun 18, 2012 at 12:14 PM, R. Michael Weylandt
<michael.weylandt at gmail.com> wrote:
> I would argue (somewhat emphatically) that the parallel facilities you
> are looking at are absolutely not for `for` loops. `for` loops are a
> control structure native to imperative programming and, as such, are
> inherently stateful. This provides many advantages, but easy
> parallelization is absolutely not one of them. Rather consider R as a
> functional language and the appropriate "control structure" is the
> Map(), most famously of MapReduce, but also inherent in R's *apply()
> family of functions. The careful reader will note that here is where
> parallelization is exposed. By being state-free, there's no inherent
> sequentiality and, consequently, no barriers to parallel computing.
>
> For a somewhat concrete example consider what it would take to do a
> state-dependent simulation (like a gibbs sampler) in parallel: it is,
> to my mind, quite non-trivial. Compare this to the question of doing
> column sums of a matrix in parallel -- effectively trivial. The
> parallelization afforded by R is of that second sort.
>
> A red herring in this discussion is the foreach() formalism, but a
> moment's thought suggests to me that foreach() is much closer to Map()
> than to for().
>
> Best,
> Michael
>
> On Sun, Jun 17, 2012 at 1:23 PM, Gary Dong <pdxgary163 at gmail.com> wrote:
>> Thanks for all replied.
>>
>> I read the introduction of R parallel. Is it for loops only?
>>
>> Gary
>>
>>
>> On Sun, Jun 17, 2012 at 10:04 AM, R. Michael Weylandt
>> <michael.weylandt at gmail.com> <michael.weylandt at gmail.com> wrote:
>>>
>>> Take a look at the parallel package which ships with all current versions
>>> of R.
>>>
>>> Michael
>>>
>>> On Jun 17, 2012, at 11:39 AM, Gary Dong <pdxgary163 at gmail.com> wrote:
>>>
>>> > Dear R users,
>>> >
>>> > I'm wonder if there is a easy way to make R use multi-CPUs on my
>>> > computer.
>>> > My computer has four CPUs but R uses only one. Thanks.
>>> >
>>> > Gary
>>> >
>>> >    [[alternative HTML version deleted]]
>>> >
>>> > ______________________________________________
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>>
>>
>
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