Classifier - Software Development Case Studies in Java - page 69

public class TestClassifier extends TestCase {
private DecisionTree buildTree(){
Node root # new Node("AC");
Node n1 # new Node("ABS");
Node n2 # new Node("ABS");
root.addChild("yes",n1);
root.addChild("no",n2);
Node l1 # new Node("high");
Node l2 # new Node("medium");
Node l3 # new Node("medium");
Node l4 # new Node("low");
n1.addChild("yes",l1);
n1.addChild("no",l2);
n2.addChild("yes",l3);
n2.addChild("no",l4);
return new DecisionTree(root);

}
public void testCategory(){
DecisionTree dt # buildTree();
FeatureType yn # new FeatureType("YesNo",
new String[]{"yes","no"});
Feature[] features # new Feature[] {
new Feature("AC","yes",yn),
new Feature("ABS","yes",yn) };
Item item # new Item("car",features);
String category # dt.assignCategory(item);
assertEquals("high",category);
item.setValue("AC","no");
category # dt.assignCategory(item);
assertEquals("medium",category);
item.setValue("AC","yes");
item.setValue("ABS","no");
category # dt.assignCategory(item);
assertEquals("medium",category);
item.setValue("AC","no");
category # dt.assignCategory(item);
assertEquals("low",category);

}

}

4.5 ■ Prototype 2: Criteria representation

The prototype developed in this iteration provides a textual representation
of the decision tree. The representation has the goal of being easy to under-
stand, so it can be used as feedback to the problem expert.