ws_1.sagews

g = graphs.PetersenGraph()
g.show()
show(graphs.PetersenGraph())A = g.adjacency_matrix()
A
AI = g.incidence_matrix()
AI

[0 1 0 0 1 1 0 0 0 0] [1 0 1 0 0 0 1 0 0 0] [0 1 0 1 0 0 0 1 0 0] [0 0 1 0 1 0 0 0 1 0] [1 0 0 1 0 0 0 0 0 1] [1 0 0 0 0 0 0 1 1 0] [0 1 0 0 0 0 0 0 1 1] [0 0 1 0 0 1 0 0 0 1] [0 0 0 1 0 1 1 0 0 0] [0 0 0 0 1 0 1 1 0 0] [1 1 1 0 0 0 0 0 0 0 0 0 0 0 0] [1 0 0 1 1 0 0 0 0 0 0 0 0 0 0] [0 0 0 1 0 1 1 0 0 0 0 0 0 0 0] [0 0 0 0 0 1 0 1 1 0 0 0 0 0 0] [0 1 0 0 0 0 0 1 0 1 0 0 0 0 0] [0 0 1 0 0 0 0 0 0 0 1 1 0 0 0] [0 0 0 0 1 0 0 0 0 0 0 0 1 1 0] [0 0 0 0 0 0 1 0 0 0 1 0 0 0 1] [0 0 0 0 0 0 0 0 1 0 0 1 1 0 0] [0 0 0 0 0 0 0 0 0 1 0 0 0 1 1]

#g = Graph([(0,1),(1,2),(2,3),(0,3)])
#g.show()
M = Matrix([
        [0,1,1,1],
        [1,1,1,0],
        [1,1,0,1],
    ]);
M
type(M)
g = BipartiteGraph(M)
g.plot()

[0 1 1 1] [1 1 1 0] [1 1 0 1] <type 'sage.matrix.matrix_integer_dense.Matrix_integer_dense'>

g = graphs.PetersenGraph()
print "# vertices = order = " + str(g.order());
print "# edges = size = " + str(g.size());
g.show() # long time
g.add_edges([[0,9],[1,5]])
g.show() # long time
S = g.subgraph([5,6,7,8,9])
S.show()
S = g.subgraph([0,1,2,3,4])
S.show()

# vertices = order = 10 # edges = size = 15

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