[R] CART with a circular response

[Terry Therneau]

> Could anyone advise me how can I implement classification and
> regression tree analyses for a circular response (angles)?

Rpart allows for user-defined splitting rules.  You need to define a
function which is given y and an ordered x, and returns the 'goodness of
split' for each split point.  You need to decide how to define
"goodness".

Terry Therneau