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Addressing Columns in a Data Frame

3 messages · Lorenzo Isella, R. Michael Weylandt, Denis Francisci

Lorenzo Isella
# 
Dear All,
Probably a one liner, but I am banging my head against the floor.
Consider the following

DF <- data.frame(
    x=1:10,
    y=10:1,
    z=rep(5,10),
    a=11:20
  )

mn<-names(DF)

but then I cannot retrieve a column by doing e.g,

DF$mn[2]

I tried to play with the quotes and so on, but so far with no avail.
Any suggestion is welcome.
Cheers

Lorenzo
R. Michael Weylandt
#
On Feb 9, 2013, at 1:40 PM, Lorenzo Isella <lorenzo.isella at gmail.com> wrote:

            

      
      
      
    

        
$ doesn't evaluate it's arguments so I think you want something like: DF[[mn[2]]] or DF[,mn[2]] 

Cheers,
MW

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Denis Francisci
    

    

      
      #
    

  


  

      
I don't know if I understood your problem, but maybe you can retrieve
your columns simply in this way:

            

      
      
      
    

        
[1] 10  9  8  7  6  5  4  3  2  1

or (for looking at column)

            

      
      
      
    

        
y
1  10
2   9
3   8
4   7
5   6
6   5
7   4
8   3
9   2
10  1

Bye
D.


2013/2/9 Lorenzo Isella <lorenzo.isella at gmail.com>: