momepy：如何使用 GeoDataframe 点和线串来构建 Networkx 图？

Question

我有 2 个 GeoDataframes，一个是点对象，另一个是线串。点在线串上。我如何使用这 2 个 gdfs 来构建 networkx 图？

#  Import
import osmnx as ox
import networkx as nx
import os
os.environ['USE_PYGEOS'] = '0'
import pandas as pd
import geopandas as gpd
import matplotlib.pyplot as plt



# Data

gdf1_line.head()
index line_code line_direc  geometry
0   77  0   LINESTRING (12948661.614 4856347.606, 12948661...
1   335 0   LINESTRING (12945808.586 4844253.556, 12945806...
2   323 0   LINESTRING (12949768.231 4862490.823, 12949825...
3   349 0   LINESTRING (12949059.428 4850398.713, 12949059...
4   349 1   LINESTRING (12941150.014 4842236.071, 12941144...


gdf2_line.head()
index staion_id line_code   order_inLine    geometry
4563    657844  323 1   POINT (12949768.231 4862490.823)
4564    657845  323 2   POINT (12950200.654 4862400.385)
4565    657846  323 3   POINT (12950221.658 4861898.833)
4566    657847  323 4   POINT (12950051.957 4861245.409)
4567    657848  323 5   POINT (12949078.265 4861197.891)  

 

# Plot
fig,ax = plt.subplots(figsize=(20,10)) 
gdf1_line.plot(ax=ax,color='grey',label='bus line',zorder=1,alpha=0.8)
gdf2_points.plot(ax=ax,label='bus on station',zorder=2,marker='^',markersize=5,color='blue',alpha=0.4)   
plt.axis('off')
plt.legend()
plt.show() 

# Try

import momepy
graph = momepy.gdf_to_nx(gdf1_line,approach='primal')
nx.draw(graph,{n:[n[0], n[1]] for n in list(graph.nodes)},node_size=15)

新发现

当我用29 POINTS建一个LineString，用momepy.gdf_to_nx函数建图时，图中的节点数变成了2，这是怎么回事？

# data    
s
line_code   bus_direct  geometry
0   323 0   LINESTRING (12949768.231 4862490.823, 12950200...
# draw    
position = {n:[n[0], n[1]] for n in list(graph.nodes)} 
f, ax = plt.subplots(1, 2, figsize=(10, 6), sharex=True, sharey=True)
for i, facet in enumerate(ax):
    facet.set_title(("gpd line", "nx graph")[i])
    facet.axis("off")
s.plot(color='orange',ax = ax[0])
graph = momepy.gdf_to_nx(s,approach='primal')
nx.draw(graph,position,ax=ax[1],node_size=15)

我希望当我绘制图表时，它会与 GeoDataframes 的实际位置一致。