划分北美答案

【问题标题】：Partitioning North America划分北美
【发布时间】：2023-04-11 02:28:01
【问题描述】：

我的目标是创造：

这是北美的 Voronoi 图。问题是当我运行我的代码时，错误通知我IndexError: tuple index out of range。我不知道为什么会出现这个错误，我不确定如何解决它。

这是我的代码：

import matplotlib.pyplot as plt
import geopandas as gpd
from shapely.ops import cascaded_union
from geovoronoi.plotting import subplot_for_map, plot_voronoi_polys_with_points_in_area
from geovoronoi import voronoi_regions_from_coords, points_to_coords

cities = gpd.read_file('world_populated_cities.csv')
world = gpd.read_file(gpd.datasets.get_path('naturalearth_lowres'))
na = world[world.continent == 'North America']

#cities = cities.geometry.to_crs(epsg=3857)
#na = na.to_crs(epsg=3857)
cities.crs = "EPSG:3857"
na.crs = "EPSG:3857"

na_shape = cascaded_union(na.geometry)
cities = cities.to_crs(na.crs)   # convert city coordinates to same CRS!

cities = cities[cities.geometry.within(na_shape)]

coords = points_to_coords(cities.geometry)
poly_shapes, pts, poly_to_pt_assignments = voronoi_regions_from_coords(coords, na_shape)

fig, ax = subplot_for_map()
plot_voronoi_polys_with_points_in_area(ax, na_shape, poly_shapes, coords)
ax.set_title('Cities data for South America from GeoPandas\nand Voronoi regions around them')
plt.tight_layout()
plt.savefig('using_geopandas.png')
plt.show()

我的代码也可以在这里找到（Google Colab Notebook）：https://colab.research.google.com/drive/1oDhWsbnrwLAKXpi-f8fhJlsdxhuQrxzw

我对 geopandas 比较陌生，因此非常感谢任何帮助！

【问题讨论】：

见the docs on Managing Projections: Setting a Projection。
@MisterMiyagi 谢谢，我相应地调整了我的代码，根据文档通过cities.crs = "EPSG:3857" 设置城市的 crs。虽然已经解决了 crs 错误，但我现在有一个 IndexError: tuple index out of range 错误。不知道如何进行；
请为您的错误提供完整的追溯。

标签： python geo voronoi

【解决方案1】：

如果有人偶然发现这一点，可以通过设置正确的投影来生成绘图：

import matplotlib.pyplot as plt
import geopandas as gpd
from shapely.ops import cascaded_union
from geovoronoi.plotting import subplot_for_map, plot_voronoi_polys_with_points_in_area
from geovoronoi import voronoi_regions_from_coords, points_to_coords
cities = gpd.read_file('world_populated_cities.csv')
world = gpd.read_file(gpd.datasets.get_path('naturalearth_lowres'))
na = world[world.continent == 'North America']
cities.crs = ({'init': 'epsg:3857'}) 
cities = cities.to_crs({'init': 'epsg:4326'}) 
na_shape = cascaded_union(na.geometry)
cities = cities[cities.geometry.within(na_shape)]
coords = points_to_coords(cities.geometry)
poly_shapes, pts, poly_to_pt_assignments = voronoi_regions_from_coords(coords, na_shape)
fig, ax = subplot_for_map()
plot_voronoi_polys_with_points_in_area(ax, na_shape, poly_shapes, coords)
ax.set_title('Cities data for South America from GeoPandas\nand Voronoi regions around them')
plt.tight_layout()

城市文件是here。

【讨论】：