How to set a maximum value in a color map of a network (Python)

问题

Imagine you have a network of 10 nodes and the nodes value is values = [i for i in range(len(10))]

Now I want to color this network however, I only want a color map of the nodes that have a value less than 5. How do I do this?

Thank you in advance.

回答1:

For that, you can simply not include (filte out) those nodes you want to avoid when plotting in nx.draw. If you do want to include them, though just without a colormap (perhaps a constant color), just use a constant color rather than removing those nodes. Here's an example using a random graph:

import networkx as nx
import matplotlib as mpl
from matplotlib import pyplot as plt

G = nx.barabasi_albert_graph(10, 1)
# defines a colormap lookup table 
nodes = sorted(list(G.nodes()))
low, *_, high = sorted(values)
norm = mpl.colors.Normalize(vmin=low, vmax=high, clip=True)
mapper = mpl.cm.ScalarMappable(norm=norm, cmap=mpl.cm.coolwarm)

To include all nodes, but have those <5 without any colormap:

plt.subplots(figsize=(10,6))
nx.draw(G, 
        nodelist=values,
        node_size=500,
        node_color=[mapper.to_rgba(i) if i>5 else 'lightblue' 
                    for i in values], 
        with_labels=True)
plt.show()

To directly remove them:

plt.subplots(figsize=(10,6))

pos = nx.spring_layout(G)
nx.draw_networkx_edges(G, pos=pos)
nx.draw_networkx_nodes(G, pos=pos,
                       nodelist=[i for i in values if i>5],
                       node_color=[mapper.to_rgba(i) 
                            for i in nodes if i>5])
nx.draw_networkx_labels(G, pos=pos,
                       labels={node:node for node in nodes if node>5})

来源：https://stackoverflow.com/questions/62863070/how-to-set-a-maximum-value-in-a-color-map-of-a-network-python

标签

python

networkx