Subscript a Tree Object
DESCRIPTION:
Returns a tree object containing the subtree rooted at the specified node, providing that node > 0. If node < 0, the nodes below the specified node will be removed from the tree object.
USAGE: 
[.tree(x, ..., drop = T)
x[node]
x[-node]
REQUIRED ARGUMENTS:
x:
Tree object, as output by the functions tree, snip.tree, or select.tree. The subscript number must reference a node number in the tree object.
VALUE:
a tree object containing the subtree rooted at node (if node > 0); otherwise the tree object with nodes below node removed.
DETAILS:
This is method for the generic "[" operator. The method relies on tree-specific functions select.tree and snip.tree to do the actual work. These functions can be called directly by users for interactive use.
SEE ALSO:
select.tree , snip.tree , Subscript , tree .
EXAMPLES: 
z.auto <- tree(Mileage ~ Weight, car.test.frame)
z.auto[7]


# Gives the following output:
node), split, n, deviance, yval
      * denotes terminal node
 7) root 22 61.320 20.41
  14) Weight<3637.5 16 32.940 21.06
    28) Weight<3322.5 10 16.500 20.50
      56) Weight<3197.5 5 11.200 20.60 *
      57) Weight>3197.5 5  5.200 20.40 *
    29) Weight>3322.5 6  8.000 22.00 *
  15) Weight>3637.5 6  3.333 18.67 *