[R] logical to vector?

[Ed Siefker]

I am trying to use the coXpress function from
the coXpress package.  This function requires
numerical vectors indicating which columns
are in which group.

The problem is, I can only figure out how
to get a logical structure, not a numerical one.
In other words, coXpress wants something like:
"1:3"

 I have something like:
TRUE TRUE TRUE FALSE FALSE

Can I convert one into the other easily?