arbor.anova
Set Up for anova Method for an Arbor Model
Description
Set up for anova method for an 
arbor model. 
Usage
arbor.anova(y, offset, parms, wt)
Value
a list consisting of y (substracting offset if necessary), 
parms, and numresp = 1).  arbor.anova is used only by the function arbor.