[R] Convert data frame entries to numbers

[John]

Hello,

I figure this is quite a simple problem really, but since I'm quite
new to R I need to ask:

If I have a data frame:

str(test) :
$ classcol: Factor w/ 3 levels "1","2","3"

How do I convert the entries in this column to numbers. I.e., I want
to be abl to do simple calculations like test[1,the_column] - test
[2,the_column] without errors.


as.numeric(test) yeilds the error "object cannot be coerced to type
'double'"


Thanks!
John