### Quick Directions

Manual Graph Editing:

• Add Customer: Mouse click in an empty space.
• Add Depot: Hold down the CONTROL key and mouse click in an empty space
• Move Customer or Depot: Hold down the SHIFT key when mouse click on a node, and drag.
• Delete Customer or Depot: Click on a node. The node is painted in red. To delete the node, hit the DELETE key.
• Edit Customer's demand: Click on a customer node. The node is painted in red. To edit the node, hit the letter e key.
• Zoom In: Drag the mouse to the desired region to zoom in on.
• Zoom Out: Press the ESCAPE key.

• File
• Show Hide Demand: show or hide the customer demands
• Show Test Results: show the last 24 test results
• Clear Graph: Resets the graph by clearing all the nodes and arcs.
• Exit: Exits the applet window.
• Generation:
• Create Customers: A Wizard helps the user to create a set of customer sites by asking a sequence of questions. The first question asks about the number of sites to be created. The choice is 50, 150, and 250 sites. The second question asks about the distribution of customer sites in the 10,000x10,000 grid. The choice is uniform (low), somehow concentrated around the depot (medium), and highly concentrated around the depot (high). In the latter case, the probability for a site to be distant from the depot decreases rapidly with the distance. It follows that most sites are concentrated in a small area surrounding the depot. A random demand between 1 and 5 is assigned to each customer. A unique depot is created.
• Solve VRP Problem:

Currently, the user has the choice among three algorithms for solving the VRP problem. The first two algorithms are based on the strategy "route first, partition later" and the last algorithm is based on the strategy "partition first, route later". Neither of the two approaches dominates the other in term of solution quality or speed. However, experience has shown that "route first, partition later" works better when the sites are uniformly distributed in the area and when the truck capacity is small with respect to the total customer demand while the latter "partition first, route later" works better when the sites are more concentrated around the depot and the truck capacity is large.

Back to the Graph Algorithms Applet