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