
ADJACENCY MATRIXName:
We make a distinction between undirected and directed adjacency matrices. For the undirected case, the order of the edges does not matter. So an edge between vertex i and vertex j means that both A_{ij} and A_{ji} will be set to 1. In the directed case, the order is relevant. So if A_{ij} = 1, this does not imply that A_{ji} = 1. Adjaency matrices are most useful when dealing with dense graphs with a relatively modest number of vertices.
where <edge1> is a variable that identifies the first vertex in the edge; <edge2> is a variable that identifies the second vertex in the edge; and <mat> is a matrix where the adjacency matrix is saved. This syntax is used for the undirected case.
where <edge1> is a variable that identifies the first vertex in the edge; <edge2> is a variable that identifies the second vertex in the edge; and <mat> is a matrix where the adjacency matrix is saved. This syntax is used for the directed case.
dimension 100 columns read edge1 edge2 2 3 4 7 1 9 7 11 5 8 2 5 6 10 2 8 3 8 4 11 end of data . let nvert = 14 let adj = adjacency matrix edge1 edge2 nvert . set write format 14F5.0 print adj
Date created: 9/8/2010 