与geopandas的动画网格计数

Question

我正在尝试将以下代码合并到动画中。下面的数据是一个可行的示例。我正在与时间戳一起工作日期和时间。

我目前将数量绘制为热图。我希望使用时间戳列随着时间的推移显示此计数的变化。

gdf_area = gpd.read_file('https://raw.githubusercontent.com/openpolis/geojson-italy/master/geojson/limits_IT_municipalities.geojson')#.loc[:, ["geometry"]]

BOXES = 50
a, b, c, d = gdf_area.total_bounds

gdf_grid = gpd.GeoDataFrame(
    geometry=[
        shapely.geometry.box(minx, miny, maxx, maxy)
        for minx, maxx in zip(np.linspace(a, c, BOXES), np.linspace(a, c, BOXES)[1:])
        for miny, maxy in zip(np.linspace(b, d, BOXES), np.linspace(b, d, BOXES)[1:])
    ],
    crs="epsg:4326",
)

gdf_grid.insert(0, 'timestamp', range(0, 0 + len(gdf_grid)))

# total area for the grid
xmin, ymin, xmax, ymax = gdf_grid.total_bounds

# how many cells across and down
n_cells = 30
cell_size = (xmax-xmin)/n_cells

# create the cells in a loop
grid_cells = []
for x0 in np.arange(xmin, xmax+cell_size, cell_size ):
        for y0 in np.arange(ymin, ymax+cell_size, cell_size):
            # bounds
            x1 = x0-cell_size
            y1 = y0+cell_size
            grid_cells.append(shapely.geometry.box(x0, y0, x1, y1))
        
cell = gpd.GeoDataFrame(grid_cells, columns = ['geometry'], crs = 'EPSG:4326')

merged = gpd.sjoin(gdf_grid, cell, how='left', predicate='within')

# make a simple count variable that we can sum
merged['gridCount'] = 1

# Compute stats per grid cell -- aggregate fires to grid cells with dissolve
dissolve = merged.dissolve(by = 'index_right', aggfunc = 'count')

# put this into cell
cell.loc[dissolve.index, 'gridCount'] = dissolve['gridCount'].values

fig, ax = plt.subplots()

im = cell.plot(column = 'gridCount', 
               cmap = 'viridis_r', 
               #vmax = 1000,
               alpha = 0.5,
               edgecolor = 'grey')

def animate(data):

    im.set_data(data)

    return im

anim = animation.FuncAnimation(fig, animate, frames = 10,
                               interval=50)

输出：

AttributeError: 'AxesSubplot' object has no attribute 'set_data'

Answer 1

我不确定时间戳，但是对于动画功能，您可以使用cell.plot（）使用ax axe 参数设置为ax ax 。以下创建了一个动画GIF，其随机生成GridCount值。您可以根据data Animate 函数的参数生成gridCount值生成GridCount值。

from random import randint

import geopandas as gpd
import matplotlib.pyplot as plt
from matplotlib import animation
import numpy as np
import shapely


gdf_area = gpd.read_file('https://raw.githubusercontent.com/openpolis/geojson-italy/master/geojson/limits_IT_municipalities.geojson')

BOXES = 50
a, b, c, d = gdf_area.total_bounds

gdf_grid = gpd.GeoDataFrame(
    geometry=[
        shapely.geometry.box(minx, miny, maxx, maxy)
        for minx, maxx in zip(np.linspace(a, c, BOXES), np.linspace(a, c, BOXES)[1:])
        for miny, maxy in zip(np.linspace(b, d, BOXES), np.linspace(b, d, BOXES)[1:])
    ],
    crs="epsg:4326",
)

# total area for the grid
xmin, ymin, xmax, ymax = gdf_grid.total_bounds

# how many cells across and down
n_cells = 30
cell_size = (xmax-xmin)/n_cells

# create the cells in a loop
grid_cells = []
for x0 in np.arange(xmin, xmax+cell_size, cell_size ):
        for y0 in np.arange(ymin, ymax+cell_size, cell_size):
            # bounds
            x1 = x0-cell_size
            y1 = y0+cell_size
            grid_cells.append(shapely.geometry.box(x0, y0, x1, y1))
cell = gpd.GeoDataFrame(grid_cells, columns = ['geometry'], crs = 'EPSG:4326')


fig = plt.figure()
ax = plt.axes()

def animate(data):
    cell['gridCount'] = [randint(1,10) for _ in range(0, len(cell))] 
    im = cell.plot(
        'gridCount', 
        cmap = 'viridis_r',         
        alpha = 0.5,
        edgecolor = 'grey',
        ax=ax,
    )
    return im

anim = animation.FuncAnimation(fig, animate,  frames = 10, interval=50)
anim.save('map.gif', writer='imagemagick')

输出：