Draw different color for nodes in networkx based on their node value

fsociety picture fsociety · Nov 22, 2012 · Viewed 38.2k times · Source

I have a large graph of nodes and directed edges. Furthermore, I have an additional list of values assigned to each node.

I now want to change the color of each node according to their node value. So e.g., drawing nodes with a very high value red and those with a low value blue (similar to a heatmap). Is this somehow easily possible to achieve? If not with networkx, I am also open for other libraries in Python.

Answer

unutbu picture unutbu · Nov 22, 2012
import networkx as nx
import numpy as np
import matplotlib.pyplot as plt

G = nx.Graph()
G.add_edges_from(
    [('A', 'B'), ('A', 'C'), ('D', 'B'), ('E', 'C'), ('E', 'F'),
     ('B', 'H'), ('B', 'G'), ('B', 'F'), ('C', 'G')])

val_map = {'A': 1.0,
           'D': 0.5714285714285714,
           'H': 0.0}

values = [val_map.get(node, 0.25) for node in G.nodes()]

nx.draw(G, cmap=plt.get_cmap('viridis'), node_color=values, with_labels=True, font_color='white')
plt.show()

yields enter image description here


The numbers in values are associated with the nodes in G.nodes(). That is to say, the first number in values is associated with the first node in G.nodes(), and similarly for the second, and so on.