Building a CART model 

Once we have the two data sets and have got a basic understanding of data, we now build a CART model. We have used “caret” and “rpart” package to build this model. However, the traditional representation of the CART model is not graphically appealing on R. Hence, we have used a package called “rattle” to make this decision tree. “Rattle” builds a more fancy and clean trees, which can be easily interpreted. Use the following code to build a tree and graphically check this tree:

modfit <- train(Species~.,method="rpart",data=training) 

library(rattle)

fancyRpartPlot(modfit$finalModel)