fitted model object of class rpart. This is assumed to be the result of some function that produces an object with the same named components as that returned by the rpart function.

the number of digits to be used for numeric values. All of the rpart functions that call labels explicitly set this value, with options("digits") as the default.

the minimum length for abbreviation of character or factor variables. If 0 no abbreviation is done; if 1 then single letters are used with "a" for the first level, "b" for the second and so on. If the value is greater than 1, the abbreviate function is used.

an argument included for backwards compatibility: pretty=0 implies minlength=0, pretty=NULL implies minlength=1, and pretty=TRUE implies minlength=4.

logical. The returned set of labels is always of the same length as the number of nodes in the tree. If collapse=TRUE (default), the returned value is a vector of labels for the branch leading into each node, with "root" as the label for the top node. If FALSE, the returned value is a two column matrix of labels for the left and right branches leading out from each node, with "leaf" as the branch labels for terminal nodes.

optional arguments to abbreviate.