[R] deleting column from data frame

[David Winsemius]

On Feb 23, 2010, at 6:04 AM, Knut Krueger wrote:

> Hi to all,
> test <- data.frame("X"=c(1:4),"Y"=c(5:8),"Z"=c(8:11))
> test <- test[,-2]
>
> Is there a way to specify the col name  "Y" to delete instead the  
> number?
>

I believe that negative indexing only works with numeric arguments.  
You could dummy up a negation approach for character vectors with:

 > test[, !(names(test) %in% c("Y"))]   #non-negated logical vector to  
index
   X  Z
1 1  8
2 2  9
3 3 10
4 4 11

 > test[, -grep("Y",names(test))]  # negated numeric vector to index
   X  Z
1 1  8
2 2  9
3 3 10
4 4 11

-- 
David
> Kind regards Knut
>
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