[R] Select certain elements from dataframe

Sebastian Eck Sebastian.Eck at helmholtz-muenchen.de
Tue May 20 10:25:00 CEST 2008


First of all thank you very much, that helped a lot!

Now I have another related problem, again I want to limit a dataframe on
certain elements, the dataframe looks like this:
> colnames(sd_all)
 [1] "X"                        "mydata.a"
 [3] "mydata.x"        "mydata.sd.a"
.
.
.
[13] "mydata.mad.x"    "snr"

X denotes the identifier and I want to select all rows which identifiers are
in a cluster.
>clusterX
[1] 101KF4319097339 102KF4319101170 103KF4319047549 104KF4319046389
[5] 125KF4319063638 126KF4319102180 127KF4319107122 128KF4319019607
.
.
.
[125] 795KS4242028634 797KS4242032582 798KS4242035374
127 Levels: 101KF4319097339 102KF4319101170 103KF4319047549 ...
798KS4242035374

I tried :
>sd_all_clusterX<-sd_all[as.character(clusterX),]

but that results in all colums being NA. for example:
>sd_all_clusterX[8]
NA                       NA
NA.1                     NA
NA.2                     NA
NA.3                     NA
.
.
NA.126                   NA

Again help would be very much appreciated,

Sebastian






jholtman wrote:
> 
> 'xx1' is a 'factor' and you have to convert to a character before
> selecting:
> 
> data.xx1<-data[ ,as.character(xx1)]
> 
> On Mon, May 19, 2008 at 5:20 AM, SebastianEck <sebastianeck at web.de> wrote:
> 
>>
>> Hello,
>>
>> I have a specific problem, I have a large dataframe, and after clustering
>> I
>> want to select certain colums, the elements of a subcluster.
>>
>> My dataframe looks like this :
>>
>> > colnames(data)
>>  [1] "101KF4319097339" "102KF4319101170" "103KF4319047549"
>> "104KF4319046389"
>>  [5] "105KF4319013260" "106KF4319025582" "107KF4319108763"
>> "108KF4319047040"
>>  [9] "109KF4319060241" "110KF4319056658" "111KF4319036131"
>> "112KF4319097194"
>> .
>> .
>> .
>> [701] "821KS4242126913" "822KS4242026026" "823KS4242003122" "824IHT06020"
>> [705] "825IHT06020"     "826IHT06005"     "827IHT06005"
>>
>> My subcluster looks like this
>>
>> > xx1
>>  xx1
>>  [1] 101KF4319097339 102KF4319101170 103KF4319047549 104KF4319046389
>>  [5] 125KF4319063638 126KF4319102180 127KF4319107122 128KF4319019607
>>  [9] 135KF4319037854 138KF4319050003 140KF4319069150 152KF4319109279
>> .
>> .
>> .
>> [125] 795KS4242028634 797KS4242032582 798KS4242035374
>> 127 Levels: 101KF4319097339 102KF4319101170 103KF4319047549 ...
>> 798KS4242035374
>>
>> Now I want to select all elements from data that are in xx1, I tried
>>
>> >data.xx1<-data[ ,xx1]
>>
>> but that selects the just the first 127 (127 is the number of elements /
>> length from xx1) elements from data.
>>
>> Any help would be very appreciated :)
>>
>> Sebastian
>> --
>> View this message in context:
>> http://www.nabble.com/Select-certain-elements-from-dataframe-tp17314209p17314209.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<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 you are trying to solve?
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> 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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