为什么在networkx中弯曲的边缘对我不起作用？

Question

因此，我想具有弯曲的边缘，并且根据documentation似乎很容易，因为我可以定义connectionstyle。因此，我尝试建立一个像这样的最小示例：

import numpy as np
import networkx as nx
import matplotlib.pyplot as plt

B = np.random.rand(5, 5)
G = nx.DiGraph(B)
A = nx.minimum_spanning_arborescence(G) # creating some arborescence, i.e. a directed graph

pos = nx.spring_layout(A)
nx.draw_networkx_nodes(A, pos, node_size=300)
nx.draw_networkx_edges(A, pos, connectionstyle='arc3, rad=0.2')