python—networkx：画随机几何图，找出中心节点并按路径长度染色

• • 随机生成一个集合图，自带路径属性，图大小为1*1，找出距离中心[0.5, 0.5]最近的节点，并按照路径染色。
    NetworkX Examples » Drawing » Random Geometric Graph
    
    
    

    <pre name="code" class="python">#coding:utf-8
    import networkx as nx
    import matplotlib.pyplot as plt
    
    G=nx.random_geometric_graph(200,0.125)
    # position is stored as node attribute data for random_geometric_graph
    pos=nx.get_node_attributes(G,'pos')
    # find node near center (0.5,0.5)找到中心节点并求最近的节点，设为ncenter
    dmin=1
    ncenter=0
    for n in pos:
        x,y=pos[n]
        d=(x-0.5)**2+(y-0.5)**2
        if d<dmin:
            ncenter=n
            dmin=d
    # color by path length from node near center颜色定为红色，程度<span style="font-family: Arial, Helvetica, sans-serif;">按距离中心点的路径长度染色</span>
    p=nx.single_source_shortest_path_length(G,ncenter)
    plt.figure(figsize=(8,8))
    nx.draw_networkx_edges(G,pos,nodelist=[ncenter],alpha=0.4)
    nx.draw_networkx_nodes(G,pos,nodelist=p.keys(),
                           node_size=80,
                           node_color=p.values(),
                           cmap=plt.cm.Reds_r)
    plt.xlim(-0.05,1.05)
    plt.ylim(-0.05,1.05)
    plt.axis('off')
    plt.savefig('random_geometric_graph.png')
    plt.show()