Decision Tree Demo Script

Data for Demo

Back to the spell book

#Install rpart.
install.packages("rpart", dependencies = TRUE, repos = "http://cran.us.r-project.org")

library(rpart)

#Data obtained from the party package https://www.tutorialspoint.com/r/r_decision_tree.htm.

#Import data via clipboard.
Reading_Skills <- read.table(file="clipboard", header = TRUE)

#Check imported data.
head(Reading_Skills)

##   nativeSpeaker age shoeSize    score
## 1           yes   5 24.83189 32.29385
## 2           yes   6 25.95238 36.63105
## 3            no  11 30.42170 49.60593
## 4           yes   7 28.66450 40.28456
## 5           yes  11 31.88207 55.46085
## 6           yes  10 30.07843 52.83124

#Build decision tree.
TREE_READING_SKILLS <- rpart(nativeSpeaker ~ age + shoeSize + score, 
                             data = Reading_Skills)

TREE_READING_SKILLS

## n= 105 
## 
## node), split, n, loss, yval, (yprob)
##       * denotes terminal node
## 
##  1) root 105 52 no (0.5047619 0.4952381)  
##    2) score< 38.61006 43  9 no (0.7906977 0.2093023) *
##    3) score>=38.61006 62 19 yes (0.3064516 0.6935484)  
##      6) age>=8.5 42 19 yes (0.4523810 0.5476190)  
##       12) score< 50.5448 23  4 no (0.8260870 0.1739130) *
##       13) score>=50.5448 19  0 yes (0.0000000 1.0000000) *
##      7) age< 8.5 20  0 yes (0.0000000 1.0000000) *

#Plot decision tree
library(rpart.plot)
rpart.plot(TREE_READING_SKILLS, extra = 102)