[R] Common elements in columns

[Silvano Cesar da Costa]

Hi Jim.

It was a very elegant way of solving the problem.

Thank you,



> Another way of solving the problem:
>
>> set.seed(1)
>> df1<-data.frame(C1=sample(LETTERS[1:25],20,replace=FALSE),value=sample(50,20,replace=FALSE))
>> set.seed(15)
>> df2<-data.frame(C1=sample(LETTERS[1:25],15,replace=FALSE),C2=1:15)
>> set.seed(3)
>> df3<-data.frame(C1=sample(LETTERS[1:10],10,replace=FALSE),B1=rnorm(10,3))
>> set.seed(5)
>> df4<-data.frame(C1=sample(LETTERS[1:15],10,replace=FALSE),A2=rnorm(10,15))
>>
>> x <- list(df1$C1, df2$C1, df3$C1, df4$C1)
>> Reduce(intersect, x)
> [1] "G" "E" "H" "J"
>>
>
>
> On Mon, Sep 3, 2012 at 7:01 AM, Silvano Cesar da Costa <silvano at uel.br>
> wrote:
>> Hi Arun,
>>
>> it's exactly what I wanted.
>>
>> Thanks a lot,
>>
>>
>>
>>> Hi,
>>> May be this might help:
>>>
>>> set.seed(1)
>>> df1<-data.frame(C1=sample(LETTERS[1:25],20,replace=FALSE),value=sample(50,20,replace=FALSE))
>>> set.seed(15)
>>> df2<-data.frame(C1=sample(LETTERS[1:25],15,replace=FALSE),C2=1:15)
>>> set.seed(3)
>>> df3<-data.frame(C1=sample(LETTERS[1:10],10,replace=FALSE),B1=rnorm(10,3))
>>> set.seed(5)
>>> df4<-data.frame(C1=sample(LETTERS[1:15],10,replace=FALSE),A2=rnorm(10,15))
>>> df1$C1[df1$C1%in%df2$C1[df2$C1%in%df3$C1[df3$C1%in%df4$C1]]]
>>> #[1] G E H J
>>> A.K.
>>>
>>>
>>>
>>> ----- Original Message -----
>>> From: Silvano Cesar da Costa <silvano at uel.br>
>>> To: r-help at r-project.org
>>> Cc:
>>> Sent: Sunday, September 2, 2012 7:05 PM
>>> Subject: [R] Common elements in columns
>>>
>>> Hi,
>>>
>>> I have 4 files with 10000 individuals in each file and 10 columns each.
>>> One of the columns, say C1, may have elements in common with the other
>>> columns C1 of other files.
>>>
>>> If I have only 2 files, I can do this check with the command:
>>>
>>> data1[data1 %in% data2]
>>> data2[data2 %in% data1]
>>>
>>> How do I check which common elements in the columns of C1 4 files?
>>>
>>> Thanks,
>>>
>>> ---------------------------------------------
>>> Silvano Cesar da Costa
>>>
>>> Universidade Estadual de Londrina
>>> Centro de Ciências Exatas
>>> Departamento de Estatística
>>>
>>> Fone: (43) 3371-4346
>>>
>>> ______________________________________________
>>> 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.
>>>
>>>
>>>
>>
>>
>> ---------------------------------------------
>> Silvano Cesar da Costa
>>
>> Universidade Estadual de Londrina
>> Centro de Ciências Exatas
>> Departamento de Estatística
>>
>> Fone: (43) 3371-4346
>>
>> ______________________________________________
>> 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
> Data Munger Guru
>
> What is the problem that you are trying to solve?
> Tell me what you want to do, not how you want to do it.
>
>


---------------------------------------------
Silvano Cesar da Costa

Universidade Estadual de Londrina
Centro de Ciências Exatas
Departamento de Estatística

Fone: (43) 3371-4346