Topological sorting of the vertices
This functionality does not run in MATLAB.
Graph::topSort(G
)
Graph::topSort(G)
computes a topological
sorting of the graph G
, i.e., a numbering T of
the vertices, such that T_{i} < T_{j} whenever
there is an edge [i, j] in
the graph. Single vertices are positioned at the beginning.
Graph::topSort
returns a list containing
two tables. The first table holds the ordering of the vertices. The
second table shows the predecessors of each vertex. If several vertex u_{i} precede
a vertex v,
the first vertex in the ordering of u_{i} is
the predecessor of v.
If no predecessor exist, the value will be infinity.
Note:
If 
A "butterfly" graph that is decomposed in three strongly connected components:
G1 := Graph([a, b, c, d, e, f], [[a, b], [a, c], [a, d], [c, e], [d, e]], Directed): Graph::topSort(G1)
The first table shows the ordering of the vertices. The left side holds the order for each vertex, whereas the right side holds the name of the vertex. The second table shows the predecessors of each vertex. If no predecessor exist, the right side holds infinity. Otherwise the right side holds the vertex that is the direct predecessor of the vertex on the left side. To see how the graph looks a graphical plotting helps:
plot(Graph::plotGridGraph(G1, VertexOrder = [None, b, f, a, c, None, None, None, e, None, d, None], VerticesPerLine=3))

A graph 
List containing two tables.