This Java Applet demonstrates Simple Undirected Graphing. The user creates points, then places edges between some or all of them. As this is done, the user is shown how 2 representations of the Graph, the Edge Matrix and the Adjacency List, are changed by the addition of a Node and of an Edge. Nodes and Edges are the 2 basic components of any Graph. The Edge Matrix indicates which Nodes have an Edge between them by making the value of box (Node1, Node2) = 1. For an Undirected Graph, this Matrix is symmetrical about its diagonal axis form (0,0) to (n, n). The Adjacency List shows, for each node, a list of the other nodes to which it is connected. Its size for an Undirected Graph is (# of Nodes + 2(# of Edges)). The user is also shown how an Undirected Graph can be encoded from the (sometimes sparse) Matrix of edges. This encoding assigns to each Graph a unique decimal number from which all information concerning the edges may be determined given the number of nodes. If all possible edges are drawn between the nodes, a Graph is said to be "Complete". Try drawing a Complete Graph and see what happens.

Copyright © 1997, Rachel Potvin, Rebecca Ann Michaels, Chiu Hang Patrick Fung, Razi Abbas Bokhari. All rights reserved. Reproduction of all or part of this work is permitted for educational or research use provided that this copyright notice is included in any copy. Disclaimer: this collection of notes is experimental, and does not serve as-is as a substitute for attendance in the actual class.