[R] bartlett.test in a cell?

[Fredrik Karlsson]

Dear list,

I want to apply the bartlett test of homogenity of variance between two
groups in a cell, which in turn is  created by a number of factors.

Is there a way to do this without having a zillion loops around the
data? I've played around with tapply and aggregate, but it seems the
problem with these approaches is that the 'groups' variable will have
to be supplied.

Any thoughts on how I might do this?

/Fredrik