networkx画弯曲的边

柔光的暖阳◎ 2022-09-10 06:11 161阅读 0赞

networkx里面自绘的边都是直的，当多个节点处于同一条直线还有连边的时候就特别难看。如果能否让networkx画弯曲的边，那么这种情况就可以好办的多了。

思路为：

1.  绘制节点，获取节点的pos坐标。
2.  在存在边的两个节点之间，使用贝塞尔插值生成两个节点之间曲线的节点坐标。
3.  使用LineCollection绘制线即可。

下面为整理的代码：

__author__ = 'jmh081701'
    import matplotlib.pyplot as plt
    import numpy as np
    import bezier
    from matplotlib.collections import LineCollection
    import networkx as nx
    import random
    
    G = nx.Graph()
    G.add_nodes_from([0,1,2,3])
    G.add_edge(0,1,weight=0.1)
    
    G.add_edge(1,2,weight=0.2)
    
    G.add_edge(0,2,weight=0.3)
    G.add_edge(1,3,weight=0.4)
    graph = G
    def curved_line(x0, y0, x1, y1, eps=0.2, pointn=30):
    
        x2 = (x0+x1)/2.0 + 0.1 ** (eps+abs(x0-x1)) * (-1) ** (random.randint(1,4))
        y2 = (y0+y1)/2.0 + 0.1 ** (eps+abs(y0-y1)) * (-1) ** (random.randint(1,4))
        nodes = np.asfortranarray([
            [x0, x2, x1],
            [y0, y2, y1]
        ])
        curve = bezier.Curve(nodes,
                             degree=2)
        s_vals = np.linspace(0.0, 1.0, pointn)
        data=curve.evaluate_multi(s_vals)
        x=data[0]
        y=data[1]
        segments =[]
        for index in range(0,len(x)):
            segments.append([x[index],y[index]])
        segments = [segments]
        return  segments
    def curved_graph(_graph, pos = None, eps=0.2, pointn=30):
    
        if pos == None:
            pos = nx.spring_layout(graph)
    
        for u,v in graph.edges():
            x0, y0 = pos[u]
            x1, y1 = pos[v]
            segs = curved_line(x0,y0,x1,y1)
            lc = LineCollection(segs)
            plt.gca().add_collection(lc)
            plt.gca().autoscale_view()
    
    if __name__ == '__main__':
        #画节点
        pos = nx.spring_layout(graph)
    
        nx.draw_networkx_nodes(G,pos, with_label=True)
        nx.draw_networkx_edges(G,pos)
        plt.show()
        #画曲线
        nx.draw_networkx_nodes(G,pos, with_label=True)
        curved_graph(graph,pos)
    
        plt.show()

直线连边版：  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASWNvZGluZ19GMjAxNA_size_13_color_FFFFFF_t_70_g_se_x_16]

贝塞尔曲线连边版：  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASWNvZGluZ19GMjAxNA_size_13_color_FFFFFF_t_70_g_se_x_16 1]

![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASWNvZGluZ19GMjAxNA_size_14_color_FFFFFF_t_70_g_se_x_16]

[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASWNvZGluZ19GMjAxNA_size_13_color_FFFFFF_t_70_g_se_x_16]: /images/20220829/556ef878f8d74670ae280ad0b924bca0.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASWNvZGluZ19GMjAxNA_size_13_color_FFFFFF_t_70_g_se_x_16 1]: /images/20220829/03d439a4a3394120ba99acf51a8c6f26.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASWNvZGluZ19GMjAxNA_size_14_color_FFFFFF_t_70_g_se_x_16]: /images/20220829/037e93ef7f9d488f99b39591566c63e7.png