rfortunes: I think that the formula language does allow expressions with '/' to represent nested factors but I can't check right now as there is a fire in the building where my office is located. I prefer to simply write nested factors as factor1 + factor1:factor2. -- Douglas Bates R-SIG-Mixed-Models (February 2013) #Rstats

Wed, 23 Jan 2019 16:00:02 +0100
rstats

I think that the formula language does allow expressions with '/' to represent nested factors but I can't check right now as there is a fire in the building where my office is located. I prefer to simply write nested factors as factor1 + factor1:factor2.
-- Douglas Bates
R-SIG-Mixed-Models (February 2013) #Rstats