[R] Transformation of a variable in a dataframe

[Pascal Oettli]

Hi,

Because a column name exists for "C" and "D":

 > colnames(C)
[1] "A"
 > colnames(D)
[1] "B"

One possibility:
 > A=c(1,2,3)
 > B=c(4,6,7)
 > dfab<-data.frame(A,B)
 > C=dfab$A*2
 > D=dfab$B*3
 > dfcd<-data.frame(C,D)
 > dfcd
   C  D
1 2 12
2 4 18
3 6 21
 > dfcd$C
[1] 2 4 6

HTH,
Pascal


On 04/17/2013 02:33 PM, jpm miao wrote:
> HI,
>     I have a dataframe with two variable A, B. I transform the two variable
> and name them as C, D and save it in a dataframe  dfcd. However, I wonder
> why can't I call them by dfcd$C and dfcd$D?
>
>     Thanks,
>
> Miao
>
>> A=c(1,2,3)
>> B=c(4,6,7)
>> dfab<-data.frame(A,B)
>> C=dfab["A"]*2
>> D=dfab["B"]*3
>> dfcd<-data.frame(C,D)
>> dfcd
>    A  B
> 1 2 12
> 2 4 18
> 3 6 21
>> dfcd$C
> NULL
>> dfcd$A
> [1] 2 4 6
>
> 	[[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.
>