summary.itree: Summarize a Fitted itree Object

In itree: Tools for classification and regression trees, with an emphasis on interpretability.

Description

Returns a detailed listing of a fitted itree object. Same code and returned value as rpart but with additional info regarding penalties and any new parameters specific to itree objects.

Usage

## S3 method for class 'itree'
summary(object, cp=0, digits=getOption("digits"), file, ...)

Arguments

object	fitted model object of class itree. This is assumed to be the result of some function that produces an object with the same named components as that returned by the itree function.
digits	Number of significant digits to be used in the result.
cp	trim nodes with a complexity of less than cp from the listing.
file	write the output to a given file name. (Full listings of a tree are often quite long).
...	arguments to be passed to or from other methods.

Details

This function is a method for the generic function summary for class "itree". It can be invoked by calling summary for an object of the appropriate class, or directly by calling summary.itree regardless of the class of the object.

See Also

summary, itree.object, printcp.

Examples

#rpart's example:
z.auto <- itree(Mileage ~ Weight, car.test.frame)
summary(z.auto)

Example output

itree is based on the code of rpart.
Bug reports should be directed to this package's maintainer, not rparts'.

Call:
itree(formula = Mileage ~ Weight, data = car.test.frame)
  n= 60 

          CP nsplit rel error    xerror       xstd
1 0.59534912      0 1.0000000 1.0246617 0.17622780
2 0.13452819      1 0.4046509 0.5053761 0.07447379
3 0.01282843      2 0.2701227 0.3805470 0.06203073
4 0.01000000      3 0.2572943 0.3964684 0.06181435

Node number 1: 60 observations,    complexity param=0.5953491
  mean=24.58333, MSE=22.57639 
  left son=2 (45 obs) right son=3 (15 obs)
  Primary splits:
      Weight < 2567.5 to the right, improve=0.5953491, (0 missing)

Node number 2: 45 observations,    complexity param=0.1345282
  mean=22.46667, MSE=8.026667 
  left son=4 (22 obs) right son=5 (23 obs)
  Primary splits:
      Weight < 3087.5 to the right, improve=0.5045118, (0 missing)

Node number 3: 15 observations
  mean=30.93333, MSE=12.46222 

Node number 4: 22 observations
  mean=20.40909, MSE=2.78719 

Node number 5: 23 observations,    complexity param=0.01282843
  mean=24.43478, MSE=5.115312 
  left son=10 (15 obs) right son=11 (8 obs)
  Primary splits:
      Weight < 2747.5 to the right, improve=0.1476996, (0 missing)

Node number 10: 15 observations
  mean=23.8, MSE=4.026667 

Node number 11: 8 observations
  mean=25.625, MSE=4.984375 

itree documentation built on May 2, 2019, 7:25 a.m.