Evaluate a Decision Tree
Updated: Aug 28, 2026
package com.northconcepts.datapipeline.foundations.examples.decisiontree;
import com.northconcepts.datapipeline.core.Record;
import com.northconcepts.datapipeline.foundations.decisiontree.DecisionTree;
import com.northconcepts.datapipeline.foundations.decisiontree.DecisionTreeNode;
import com.northconcepts.datapipeline.foundations.decisiontree.DecisionTreeResult;
import com.northconcepts.datapipeline.internal.expression.DefaultExpressionContext;
public class EvaluateADecisionTree {
public static void main(String[] args) {
DefaultExpressionContext input = new DefaultExpressionContext();
input.setValue("Age", 49);
input.setValue("houseOwned", true);
input.setValue("Income", 1000.0);
DecisionTree tree = new DecisionTree().setRootNode(new DecisionTreeNode()
.addNode(new DecisionTreeNode("Age >= 40")
.addNode(new DecisionTreeNode("houseOwned == true").addOutcome("Eligible", "true"))
.addNode(new DecisionTreeNode("houseOwned == false")
.addNode(new DecisionTreeNode("Income >= 2000").addOutcome("Eligible", "true"))
.addNode(new DecisionTreeNode("Income < 2000").addOutcome("Eligible", "false"))))
.addNode(new DecisionTreeNode("Age < 40")
.addNode(new DecisionTreeNode("Income >= 3000").addOutcome("Eligible", "true"))
.addNode(new DecisionTreeNode("Income < 3000").addOutcome("Eligible", "false"))));
DecisionTreeResult result = tree.evaluate(input);
Record outcome = result.getOutcome();
System.out.println("outcome = " + outcome);
}
}
