You can do it `by hand' by growing a `stump' first using only that variable.
Then split the data in two pieces according to that `stump', and grow
separate trees on the pieces.
Andy
> From: lsdst8+@pitt.edu
>
>
> I would like to force a specific variable to always be the
> first split criterion in rpart3, somewhat analagous to
> forcing a variable into a stepwise regression. I have not
> come across this in any of the literature (I might have just
> missed it). Can this be done? If so what steps do I have to
> take? Thanks
>
> Scott
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