[R] Faster way to implement this search?

Jeff Newmiller jdnewmil at dcn.davis.ca.us
Sat Mar 17 06:53:00 CET 2012


Succinct is good, but reproducible is even more important.

Think ?dput or ?sample so we have some data like you do, your current algorithm, or at least a desired output example (again using dput)
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Sent from my phone. Please excuse my brevity.

Walter Anderson <wandrson01 at gmail.com> wrote:

>On 03/16/2012 12:23 PM, Sarah Goslee wrote:
>> There's almost certainly a better way, but I'd be more inclined to
>look for
>> it if you'd provide a small reproducible example so I could actually
>try it.
>> Without knowing the structure of your data, it's very hard to offer
>> alternatives.
>>
>> Sarah
>>
>> On Fri, Mar 16, 2012 at 12:59 PM, Walter
>Anderson<wandrson01 at gmail.com>  wrote:
>>> I am working on a simulation where I need to count the number of
>matches for
>>> an arbitrary pattern in a large sequence of binomial factors.  My
>current
>>> code is
>>>
>>>     for(indx in 1:(length(bin.05)-3))
>>>       if ((bin.05[indx] == test.pattern[1])&&  (bin.05[indx+1] ==
>>> test.pattern[2])&&  (bin.05[indx+2] == test.pattern[3]))
>>>         return.values$count.match.pattern[1] =
>>> return.values$count.match.pattern[1] + 1
>>>
>>> Since I am running the above code for each simulation multiple times
>on
>>> sequences of 10,000,000 factors the code is taking longer than I
>would like.
>>>    Is there a better (more "R" way of achieving the same answer?
>>>
>>> Walter Anderson
>>>
>Thank you for responding.  I was attempting to keep my code snippet 
>small, since my last question which contained what I thought was a
>small 
>(but complete example) only received responses that the
>provided code was not succinct enough.
>
>the provided sequence of factors (bin.05) consist of a vector of up of 
>factors like this; [T,T,O,T,O,O,T,T,T,...] in a variety of different 
>proportions.  The search pattern consists of any one of the
>combinations 
>of the factors (T & O) in a set of three, ie. [T,T,O]
>
>______________________________________________
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>PLEASE do read the posting guide
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>and provide commented, minimal, self-contained, reproducible code.



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