Articulation Points ¶
Articulation Points¶
This example shows how to compute and visualize the articulation points in a graph using articulation_points()
. For an example on bridges instead, see Bridges.
import igraph as ig
import matplotlib.pyplot as plt
# Construct graph
g = ig.Graph.Formula(
"0-1-2-0, 3:4:5:6 - 3:4:5:6, 2-3-7-8",
)
# Find the set of articulation points as a vertex sequence
articulation_points = g.vs[g.articulation_points()]
# Plot graph
fig, ax = plt.subplots()
ig.plot(
g,
target=ax,
vertex_size=0.3,
vertex_color="lightblue",
vertex_label=range(g.vcount()),
vertex_frame_color = ["red" if v in articulation_points else "black" for v in g.vs],
vertex_frame_width = [3 if v in articulation_points else 1 for v in g.vs],
edge_width=0.8,
edge_color='gray'
)
plt.show()
The plot looks like this:

Articulation points are marked with a red border.¶