[R] assign a cluster based on a variable

[Uwe Ligges]

On 09.06.2011 14:31, Dominik P.H. Kalisch wrote:
> Hi Uwe,
>
> thanks for your help. I didn't know that function (mea culpa)...
> With merge() it works what I want to do.
> But I'm still interessted, for a learning purpose, why the loop didn't
> work. So here are the str() results:
>
>> str(cluster)
>   int [1:18, 1:2] 12051000 12052000 12053000 12054000 12060000 12061000
> 12062000 12063000 12064000 12065000 ...
>   - attr(*, "dimnames")=List of 2
>    ..$ : chr [1:18] "1" "2" "3" "4" ...
>    ..$ : chr [1:2] "Kreis" "Cluster"
>
>> str(KreisSA)
>   num [1:2302, 1:2] 12069000 12072000 12067000 12060000 12070000 ...
>   - attr(*, "dimnames")=List of 2
>    ..$ : NULL
>    ..$ : chr [1:2] "Kreis" "Cluster"


So KreisSA is a 2 column matrix rather than a vector. Hence you also get 
2 column matrix (logical) from the comparison KreisSA == cluster[i,1] 
and so you are assigning into KreisSAa.

Uwe Ligges



> Thanks for your help.
>
>
> On Tue, 07 Jun 2011 22:49:04 +0200, Uwe Ligges
> <ligges at statistik.tu-dortmund.de>  wrote:
>> On 07.06.2011 16:24, Dominik P.H. Kalisch wrote:
>>> Hi,
>>>
>>> I have two matrices of the following form:
>>>
>>> cluster (n=18):
>>> 12062 1
>>> 12063 2
>>> 12064 2
>>> 12065 3
>>> 12066 5
>>>
>>> KreisSA (n=2304)
>>> 12062
>>> 12062
>>> 12067
>>> 12065
>>> 12063
>>> 12067
>>>
>>> I try to assign the cluster[,2] to KreisSAa by the follwoing loop:
>>>
>>> n<- nrow(cluster)
>>> KreisSAa<- numeric()
>>>
>>> for(i in 1:n){
>>> KreisSAa[KreisSA == cluster[i,1]]<- cluster[i,2]
>>> }
>>>
>>> The result is a vector of the length n=4608 where after the entry 2304
>>> are just NA's
>>> Has someone an idea what I do wrong?
>>
>> Since we do not know the structure of your objects, we cannot say
>> easily. You may want to provide
>>
>> str(cluster)
>> and
>> str(KreisSA)
>>
>> Anyway: I'd just use merge()
>>
>> Uwe Ligges
>>
>>
>>
>>
>>
>>
>>> Thanks for your help.
>>> Dominik
>>>
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>>> http://www.R-project.org/posting-guide.html
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>
> ______________________________________________
> 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.