This is an extensive suite of functions for working with simple graphs (undirected graphs without loops or multiple edges). It includes three new classes: graph, permutation, partition. A few of the functions require the Optimization Toolbox.
PLEASE READ THE DOCUMENTATION because graph objects are defined in an unusual way that makes passing them to functions efficient and enables functions to modify their graph argument. See http://www.ams.jhu.edu/~ers/matgraph/