t repetition</a></li>
            </ul>
         </div>
         <h2>Sparse matrices as graphs<a name="1"></a></h2>
         <p>To store the connectivity structure of the graph, gaimc uses the adjacency matrix of a graph.</p>
         <p>A graph is represented by a set of vertices and a set of edges between the vertices.  Often, we write <img src="demo_eq91421.png" alt="$G = (V,E)$"> to denote the graph, the set of vertices, and the set of edges, respectively.  In gaimc, like in my other package MatlabBGL,
