[R] How to avoid "$ operator is invalid for atomic vectors"

[cruz]

Thanks for all the responses, they are all very helpful:)

> you don't need to assign dimension or classes to your objects.
> It's easier if you  do like this

this is something that really bothers me, when I need to define an
object which i will later fill with data, the dimension of this object
should not be fixed because it will grow...

so in MATLAB, i.e. we define x = [ ],
what about in R?

Thanks,
cruz