请问:用rpart函数做决策树时,如何提取出决策树的规则呢?用summary(fit)只能得到每个节点的信息,例如:
> fit <- rpart(Kyphosis ~ Age + Number + Start, data = kyphosis)
> fit
n= 81
node), split, n, loss, yval, (yprob)
* denotes terminal node
1) root 81 17 absent (0.79012346 0.20987654)
2) Start>=8.5 62 6 absent (0.90322581 0.09677419)
4) Start>=14.5 29 0 absent (1.00000000 0.00000000) *
5) Start< 14.5 33 6 absent (0.81818182 0.18181818)
10) Age< 55 12 0 absent (1.00000000 0.00000000) *
11) Age>=55 21 6 absent (0.71428571 0.28571429)
22) Age>=111 14 2 absent (0.85714286 0.14285714) *
23) Age< 111 7 3 present (0.42857143 0.57142857) *
3) Start< 8.5 19 8 present (0.42105263 0.57894737) *
我想得到的是提取出它的决策规则:
rule1: if start >= 8.5 and start >=14.5 then y= absent
请问,要想得到上述类似的决策规则,应该用哪个函数?
谢谢!