The incidence matrix of a directed graph is a matrix B where n and m are the number of vertices and edges respectively, such that if the edge e<sub>j</sub> leaves vertex v<sub>i</sub>, 1 if it enters vertex v<sub>i</sub> and 0 otherwise (many authors use the opposite sign convention). | The incidence matrix of a directed graph is a matrix B where n and m are the number of vertices and edges respectively, such that if the edge e<sub>j</sub> leaves vertex v<sub>i</sub>, 1 if it enters vertex v<sub>i</sub> and 0 otherwise (many authors use the opposite sign convention). |