Python, graphes et networkx

Quelques essais sous thonny

Essai de la bibliothèque networkx

Sources

https://iut-info.univ-reims.fr/users/blanchard/ISN20181218/utilisation-de-la-bibliotheque-networkx.html#analyse-dun-reseau-social-dorques

Graphe simple

import networkx as nx

import numpy as np

import matplotlib.pyplot as plt

g = nx.Graph() # DiGraph() pour un graphe orienté

g.add_nodes_from(range(5))

g.add_edges_from([(0,1),(0,4),(0,3),(4,2),(1,3),(4,0),(1,2)])

print(g.degree())

print(g.number_of_nodes())

print(g.number_of_edges())

plt.figure()

nx.draw(g,with_labels=True)

plt.show()

>>>

[(0, 3), (1, 3), (2, 2), (3, 2), (4, 2)]

5

6

Graphe orienté

import networkx as nx

import numpy as np

import matplotlib.pyplot as plt

g = nx.DiGraph() # DiGraph() pour un graphe orienté

g.add_nodes_from(range(5))

g.add_edges_from([(0,1),(0,4),(0,3),(4,2),(1,3),(4,0),(1,2)])

print(g.degree())

print(g.number_of_nodes())

print(g.number_of_edges())

plt.figure()

nx.draw(g,with_labels=True)

plt.show()

>>>

[(0, 4), (1, 3), (2, 2), (3, 2), (4, 3)]

5

7

Deux graphes

import networkx as nx

import numpy as np

import matplotlib.pyplot as plt

g = nx.Graph() # DiGraph() pour un graphe orienté

g.add_nodes_from(range(5))

g.add_edges_from([(0,1),(0,4),(0,3),(4,2),(1,3),(4,0),(1,2)])

h=nx.Graph()

h.add_nodes_from(['a','b','c','d'])

h.add_edges_from([('a','b'),('b','c'),('c','d'),('d','a')])

print(g.degree())

print(g.number_of_nodes())

print(g.number_of_edges())

plt.figure()

nx.draw(g,with_labels=True,node_color="blue")

nx.draw(h,with_labels=True,node_color="red")

plt.show()

Graphe et voisin

Je découvre que les points et noeuds sont dans un dictionnaire

import networkx as nx

import numpy as np

import matplotlib.pyplot as plt

sommets=[1,2,3,4]

g = nx.Graph() # DiGraph() pour un graphe orienté

g.add_nodes_from(sommets)

g.add_edges_from([(1,4),(1,3),(1,2),(3,2),(4,2)])

print(g.number_of_nodes())

print(g.number_of_edges())

print(g.degree())

for i in g.nodes:

    voisin=nx.all_neighbors(g,i)

    print(i,len(list(voisin)))

print(type(voisin))

plt.figure()

nx.draw(g,with_labels=True,node_color="blue")

plt.show()

Video trajet pour snt