CODEWITHSUNDEEP
pythonnetworkx
charelf
charelf

Reputation: 3815

NetworkX shows wrong colors

I am trying to plot a simple network with networkx using colors, however the colors i give the nodes are not shown on the graph...

import networkx as nx
G = nx.Graph()

G.add_nodes_from([
    (4, {"color": "red"}),
    (5, {"color": "green"}),
])

nx.draw_networkx(G)

draws this graph:

enter image description here

Why are these nodes not the color I assigned them to?

I am trying to reproduce the example from https://networkx.org/documentation/stable/tutorial.html

Upvotes: 0

Views: 413

Answers (2)

Scott Boston
Scott Boston

Reputation: 153460

Try:

import networkx as nx
G = nx.Graph()

G.add_nodes_from([
    (4, {"color": "red"}),
    (5, {"color": "green"}),
])

nx.draw_networkx(G, node_color=[i['color'] for i in dict(G.nodes(data=True)).values()])

Output:

enter image description here

Upvotes: 1

furas
furas

Reputation: 142651

Example in documentation is misleading - and it doesn't even show image with colors.

Value {"color": "red"} is not used to change color but only keep extra information in node. You could use {"first name": "James", "last name": "Bond", "number": "007"} with the same result

To set color you have to use list when you draw them

nx.draw(G, node_color=['red', 'green', 'blue'], with_labels=True)

import networkx as nx
import matplotlib.pyplot as plt

G = nx.Graph()

G.add_nodes_from([
    (4, {"color": "red"}),
    (5, {"color": "green"}),
    (7, {"first name": "James", "last name": "Bond", "number": "007"}),
])

nx.draw(G, node_color=['red', 'green', 'blue'], with_labels=True)
plt.show()

Or you will have to use for-loop to create list using data from nodes

import networkx as nx
import matplotlib.pyplot as plt

G = nx.Graph()

G.add_nodes_from([
    1,
    2,
    (4, {"color": "red"}),
    (5, {"color": "green"}),
    (7, {"first name": "James", "last name": "Bond", "number": "007"}),
    8,
    9,
   ('Hello', {"color": "red"}),
])

#color_map = ['red', 'green', 'blue']
color_map = []

for node in G:
    print(G.nodes[node])
    if 'color' in G.nodes[node]:
        color_map.append( G.nodes[node]['color'] )
    else: 
        color_map.append('blue')    
    
nx.draw(G, node_color=color_map, with_labels=True)
plt.show()

enter image description here

Upvotes: 1

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