[R] Name of a column

[Chuck Cleland]

X <- as.logical(rep(c(0,1), each=13))

names(X) <- LETTERS

which(X)
  N  O  P  Q  R  S  T  U  V  W  X  Y  Z
14 15 16 17 18 19 20 21 22 23 24 25 26

names(which(X))
  [1] "N" "O" "P" "Q" "R" "S" "T" "U" "V" "W" "X" "Y" "Z"

?which

David Hajage wrote:
> Hello,
> 
> My problem is quite simply, but I didn't find any solution...
> 
> I have a vector :
> 
>> truc
>    longueur30 longueur40 longueur50 longueur60 longueur70 longueur80
> longueur90
> 34      FALSE      FALSE      FALSE      FALSE       TRUE      FALSE
> FALSE
> 
> I would like to have the name of the column where there is "TRUE".
> 
>> colnames(truc)
> [1] "longueur30" "longueur40" "longueur50" "longueur60" "longueur70"
> [6] "longueur80" "longueur90"
> 
>> truc[truc == T]
> [1] TRUE
> 
>> colnames(truc[truc == T])
> NULL
> 
> How can I do it ?
> 
> Thank you for your help.
> 

-- 
Chuck Cleland, Ph.D.
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