[R] Faster Solution for a simple code?

[Chris82]

Thanks!

That's a really fast soltution. Now the R process takes a few seconds
instead of a couple of hours with my loop.

greets.


jholtman wrote:
> 
> try this:
> 
>> x
>        V1      V2 V3
> 1 5000000 3200000  0
> 2 5100000 3100000  0
> 3 5200000 3100000  0
> 4 5200000 3200000  0
>> y
>        V1      V2 V3
> 1 5000000 3200000  1
> 2 5000000 3200000  1
> 3 5200000 3100000  1
> 4 5200000 3000000  1
>> z <- merge(x, y, by=c("V1", "V2"), all.x=TRUE)
>> t(sapply(split(z, z[,1:2], drop=TRUE), function(.grp){
> +     if (any(is.na(.grp))) return(c(.grp[1,1], .grp[1,2], 0))
> +     c(.grp[1,1], .grp[1,2], nrow(.grp))
> + }))
>                    [,1]    [,2] [,3]
> 5100000.3100000 5100000 3100000    0
> 5200000.3100000 5200000 3100000    1
> 5000000.3200000 5000000 3200000    2
> 5200000.3200000 5200000 3200000    0
>>
> 
> 
> On Mon, Apr 13, 2009 at 1:06 PM, Chris82 <rubenbauar at gmx.de> wrote:
>>
>> Hi R-users,
>>
>> I create a simple code to check out how often the same numbers in y occur
>> in
>> x. For example 5000000 320000 occurs two times.
>> But the code with the loop is extremly slow. x have 6100 lines and y
>> sometimes more than 50000 lines.
>>
>> Is there any alternative code to create with R?
>>
>> thanks.
>>
>>
>> x
>>
>> 5000000 3200000 0
>> 5100000 3100000 0
>> 5200000 3100000 0
>> 5200000 3200000 0
>>
>>
>> lengthx <- length(x[,1])
>>
>> y
>>
>> 5000000 3200000 1
>> 5000000 3200000 1
>> 5200000 3100000 1
>> 5200000 3000000 1
>>
>>
>> langthy <- length(y[,1])
>>
>> for (i in 1:lengthx){
>> for (j in 1:lengthy){
>> if (x[i,1] == y[j,1]){
>> if (x[i,2] == y[j,2]){
>> x[i,3] <- x[i,3] + 1
>> }
>> }
>> }
>> }
>> x
>>
>> 1  5000000    3200000      2
>> 2  5100000    3100000      0
>> 3  5200000    3100000      1
>> 4  5200000    3200000      0
>> --
>> View this message in context:
>> http://www.nabble.com/Faster-Solution-for-a-simple-code--tp23024985p23024985.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
> 
> 
> 
> -- 
> Jim Holtman
> Cincinnati, OH
> +1 513 646 9390
> 
> What is the problem that you are trying to solve?
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
> 
> 

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