[R] Function to modify existing data.frame

[Peter Muhlberger]

I'm used to statistical languages, such as Stata, in which it's trivial to
pass a list of variables to a function & have that function modify those
variables in the existing dataset rather than create copies of the variables
or having to replace the entire dataset to change a few variables.  In R, I
suppose I could paste together the right instructions in a function and then
execute it, but is there any more straightforward way of doing this I'm
missing?

Thx,

Peter