Matplotlib 等值线图绘制两个不同的数据

Question

到目前为止，我已经通过以下方式制作了 Choropleth 地图：

fig, ax = plt.subplots(1, figsize=(32, 16))
ax.axis('off')

df.plot(column='Income Rank', scheme='quantiles', k=7,legend=True, cmap='YlOrRd_r', ax=ax)
ax.annotate(xy=(0.1, .08),  xycoords='figure fraction', horizontalalignment='left', verticalalignment='top'
            ,s='Income deprivation Rank. Lowest rank = most deprived.')

看起来像这样：

我的 DF 是这样的：

geometry    Counts  WardCode Ward Name   Income Rank                                                                
POLYGON (())    1545    N09000001   Abbey   3

所以它绘制了每个区域与我在 df 中的收入数据相关的排名。我也可以在这张地图上策划犯罪吗？我试图显示低收入和高犯罪率之间的 link。例如，用标记或可能使用不同的配色方案来代表高犯罪率地区？包含我的罪行的数据框如下所示：

WARDNAME    Counts
0   CENTRAL 3206
1   DUNCAIRN    757
2   BLACKSTAFF  584

我也有一个带有纬度和经度的犯罪 df，看起来像这样：

Crime ID    Date    Longit  Latit   Crime type  Ward Name   Ward Code
0   01  2016-01 -5.886699   54.591309  Theft    CENTRAL N08000313

我可以通过使用 Folium 并用收入值绘制 Choropleth 然后绘制犯罪作为标记来在同一张地图上绘制这两个东西的唯一方法吗？或者我可以在没有叶的情况下做吗？谢谢

Answer 1

对于具有 2 个多边形叠加层的等值线图，您需要在顶层使用（半或）透明图。让我用这个例子来证明。您需要将 geopandas 安装到运行这个。

import geopandas as gpd
import matplotlib.pyplot as plt

# load world data (provided with geopandas)
world = gpd.read_file(gpd.datasets.get_path('naturalearth_lowres'))

# select some countries (for top layer plots)
brazil = world[world.name == u'Brazil']
russia = world[world.name == u'Russia']

# grouping countries by continents for base layer
world = world[['continent', 'geometry']]  # for grouping purposes, take 2 columns
continents = world.dissolve(by='continent')  # only column 'geometry' is retained; no aggregated attribute

# plot world's continents first as base layer
ax1 = continents.plot(figsize=(12, 8), cmap='Set2')

# plot other polygons on top of the base layer
# 'facecolor' = 'None' specifies transparent area
# plot Brazil at upper level (zorder=11) using 'hatch' as symbol
# higher value of zorder causes the plot on top of layers with lower values
kwarg3s = {'facecolor': 'None', 'edgecolor': 'green', 'linewidth': 1.5, 'hatch': '|||'}
brazil.plot(zorder=11, ax=ax1, **kwarg3s)

# plot Russia at upper level using 'hatch' as symbol
kwarg4s = {'facecolor': 'None', 'edgecolor': 'red', 'linewidth': 0.5, 'hatch': 'xx'}
russia.plot(zorder=11, ax=ax1, **kwarg4s)
plt.show()

结果图：

Matplotlib 等值线图绘制两个不同的数据

Matplotlib choropleth map plotting two different pieces of data

python

matplotlib

pandas

geopandas

choropleth