关于rpart.control 4个参数的中文解释，最好有例子加以说明，谢谢！

maxcompete： the number of competitor splits retained in the output. It is useful to know not just which split was chosen, but which variable came in second, third, etc.
maxsurrogate： the number of surrogate splits retained in the output. If this is set to zero the compute time will be reduced, since approximately half of the computational time (other than setup) is used in the search for surrogate splits.
usesurrogate： how to use surrogates in the splitting process. 0 means display only; an obser-vation with a missing value for the primary split rule is not sent further downthe tree. 1 means use surrogates, in order, to split subjects missing the primary
variable; if all surrogates are missing the observation is not split. For value 2 ,ifall surrogates are missing, then send theobservation in the majority direction. A value of 0 corresponds to the action of tree, and 2 to the recommendations of Breiman et.al (1984).
surrogatestyle： controls the selection of a best surrogate. If set to 0 (default) the program uses the total number of correct classification for a potential surrogate variable, if set to 1 it uses the percent correct, calculated over the non-missing values of the surrogate. The first option more severely penalizes covariates with a large number of missing values.