[R] Common elements in columns

[jim holtman]

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.