Medium Instance Performance

Lets take a look at where we are with all the bells and whistles added. If you expand the toggle below, you will see the log file from running our code on our failed attempt to solve d657.

As stated on the TSPLIB website, the optimal solution for this problem is 48912. By looking through the logs, you see that after only about 25,000 nodes, we reach a solution with objective 48913. Unfortunately, our lower bound, while initially 99.3% of the optimal solution, increases very slowly. Using the src/output/NodeLog.java, we turned the node log into the plot below illustrating how slowly our lower bound is converging, in comparison to our upper bound. Even after creating over 300,000 nodes in branch and bound, we have quite a way to go proving optimality.

Future Directions