[R] erase columns

[Gabor Grothendieck]

michele lux <nedluk <at> yahoo.it> writes:

> Can somebody remember me which is the command to erase
> columns from a data frame?

To delete a single column assign NULL to it.  That works
because a data frame is a list and that works for lists.
Here are three examples of deleting column 5, the Species 
column, from the iris data set:

   data(iris)
   iris[,5] <- NULL  

   data(iris)
   iris$Species <- NULL

   data(iris)
   iris[,"Species"] <- NULL