CODEWITHSUNDEEP
pythonnumpymatplotlibplotgraph-drawing
Diego Silvera
Diego Silvera

Reputation: 201

Given an adjacency matrix, How to draw a graph with matplotlib?

I have an undirected graph described by its adjacency matrix (a numpy array) and I want to plot it, with vertices placed in a n-regular polygon. This code works:

n = adyacency_mathix.shape[0]
axis = np.linspace(0, 2*np.pi, n, endpoint=False)
x, y = np.cos(axis), np.sin(axis)
for i in xrange(n):
    for j in xrange(i + 1, n):
        if self.matrix[i, j] == 1:
            pyplot.plot((x[i], x[j]), (y[i], y[j]), color = 'blue')
pyplot.show()

but can be optimized.

Upvotes: 3

Views: 13185

Answers (1)

Arya McCarthy
Arya McCarthy

Reputation: 8829

You may be interested in the popular networkx project, if you're interested in simply reducing the amount of code you write.

import matplotlib.pyplot as plt
import networkx as nx

# Generating sample data
G = nx.florentine_families_graph()
adjacency_matrix = nx.adjacency_matrix(G)

# The actual work
# You may prefer `nx.from_numpy_matrix`.
G2 = nx.from_scipy_sparse_matrix(adjacency_matrix)
nx.draw_circular(G2)
plt.axis('equal')

florentine circular graph

Disclaimer: I am a contributor to networkx.

Upvotes: 11

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