[R] Select certain elements from dataframe

Sebastian Eck Sebastian.Eck at helmholtz-muenchen.de
Tue May 20 11:43:07 CEST 2008



sd_all_clusterX<-sd_all[(clusterX%in%sd_all$X),] # not tested

seems to do nothing, all elements of the original dataframe are now selected






Petr Pikal wrote:
> 
> Hi
> 
> r-help-bounces at r-project.org napsal dne 20.05.2008 10:25:00:
> 
>> 
>> 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),]
> 
> Maybe you want %in% function
> 
> sd_all_clusterX<-sd_all[clusterX%in%sd_all$X),] # not tested
> 
> Regards
> Petr
> 
> 
>> 
>> 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.
>> > 
>> > 
>> 
>> -- 
>> View this message in context: 
> http://www.nabble.com/Select-certain-elements-
>> from-dataframe-tp17314209p17335609.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.
> 
> ______________________________________________
> 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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