[R] how to NULL multiple variables of a df efficiently?

Tony Breyal tony.breyal at googlemail.com
Tue Feb 24 21:31:05 CET 2009


Another way is:

> subset(df, select=c(var.b, var.c))

though I'd be willing to bet that using %in% is probably faster.[1]

Tony

[1] Unfortuantly I'm skint :-(

On 24 Feb, 20:10, Sean Zhang <seane... at gmail.com> wrote:
> Dear R-helpers:
>
> I am an R novice and would appreciate answer to the following question.
>
> Want to delete many variables in a dataframe.
> Am able to delete one variable by assigning it as NULL
> Have a large number of variables and would like to delete them without using
> a for loop.
>
> Is there a command/function which does this job?
>
> Many thanks in advance.
>
> -Sean
>
> #Small Example:
>
> df<-data.frame(var.a=rnorm(10), var.b=rnorm(10),var.c=rnorm(10))
> df[,'var.a']<-NULL   #this works for one single variable
> df[,c('var.a','var.b')]<-NULL  #does not work for multiple variables
>
>         [[alternative HTML version deleted]]
>
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