The Accord.NET framework has its own decision tree example that we should point out as well. It takes a different, more graphical approach to decision trees, but the call is yours to make as to which you like and feel most comfortable with.

Once the data is loaded you can create your decision tree and get it ready for learning. You will see a data plot similar to what you see here, using two categories, X and Y:

The next tab will let you see the tree nodes, leafs, and decisions. There is also a top-down graphical view of the tree on the right. The most useful information is located within the Tree View on the left, where you can see the nodes, their values, and the decisions that were made:

Finally, the last tab will let you perform Model Testing: