pythonpython-2.7social-networkingnetworkx

Node size dependent on the node degree on NetworkX


I imported my Facebook data onto my computer in the form of a .json file. The data is in the format:

{
  "nodes": [
    {"name": "Alan"},
    {"name": "Bob"}
  ],
  "links": [
    {"source": 0, "target: 1"}
  ]
}

Then, I use this function:

def parse_graph(filename):
    """
    Returns networkx graph object of facebook
    social network in json format
    """
    G = nx.Graph()
    json_data = open(filename)
    data = json.load(json_data)
    # The nodes represent the names of the respective people
    # See networkx documentation for information on add_* functions
    nodes = data["nodes"]
    G.add_nodes_from([n["name"] for n in nodes])
    G.add_edges_from(
        [
            nodes[e["source"]]["name"],
            nodes[e["target"]]["name"]) for e in data["links"]
        ]
    )
    json_data.close()
    return G

to enable this .json file to be used a graph on NetworkX. If I find the degree of the nodes, the only method I know how to use is:

degree = nx.degree(p)

Where p is the graph of all my friends. Now, I want to plot the graph such that the size of the node is the same as the degree of that node. How do I do this?

Using:

nx.draw(G, node_size=degree)

didn't work and I can't think of another method.


Solution

  • Update for those using networkx 2.x

    The API has changed from v1.x to v2.x. networkx.degree no longer returns a dict but a DegreeView Object as per the documentation.

    There is a guide for migrating from 1.x to 2.x here.

    In this case it basically boils down to using dict(g.degree) instead of d = nx.degree(g).

    The updated code looks like this:

    import networkx as nx
    import matplotlib.pyplot as plt
    
    g = nx.Graph()
    g.add_edges_from([(1,2), (2,3), (2,4), (3,4)])
    
    d = dict(g.degree)
    
    nx.draw(g, nodelist=d.keys(), node_size=[v * 100 for v in d.values()])
    plt.show()
    

    nx.degree(p) returns a dict while the node_size keywod argument needs a scalar or an array of sizes. You can use the dict nx.degree returns like this:

    import networkx as nx
    import matplotlib.pyplot as plt
    
    g = nx.Graph()
    g.add_edges_from([(1,2), (2,3), (2,4), (3,4)])
    
    d = nx.degree(g)
    
    nx.draw(g, nodelist=d.keys(), node_size=[v * 100 for v in d.values()])
    plt.show()
    

    enter image description here