使用 shapely 指向多边形？

Question

我是运行以下脚本，我认为应该为多边形中的点返回 TRUE，但它返回 FALSE。

from shapely import geometry

polygon = [(-1571236.8349707182, 8989180.222117377), (1599362.9654156454, 8924317.946336618), (-1653179.0745812152, 8922145.163675062), (-1626237.6614402141, 8986445.107619021)]

Point_X = -1627875.474
Point_Y = 8955472.968

line = geometry.LineString(polygon)
point = geometry.Point(Point_X, Point_Y)

print(line.contains(point))

当我在 Matlab 中绘制多边形和点时，我得到以下形状

from matplotlib import pylab as plt
poly = [[-1571236.8349707182, 8989180.222117377],
    [1599362.9654156454, 8924317.946336618],
    [-1653179.0745812152, 8922145.163675062],
    [-1626237.6614402141, 8986445.107619021]]

x = [point[0] for point in poly]
y = [point[1] for point in poly]

p1 = [-1627875.474, 8955472.968]
p2 = [-1627875.474, 8955472.968]
plt.plot(x,y,p1[0],p1[1],'*r',p2[0],p2[1],'*b')
plt.show()

知道为什么 shapely 脚本返回 FALSE 吗？

Answer 1

你测试的是你的点是否在对象LineString上。

如果要测试该点是否在多边形中，则必须使用 class Polygon

的 contains 方法

from shapely import geometry

polygon = [(-1571236.8349707182, 8989180.222117377), (1599362.9654156454, 8924317.946336618), (-1653179.0745812152, 8922145.163675062), (-1626237.6614402141, 8986445.107619021)]

Point_X = -1627875.474
Point_Y = 8955472.968

line = geometry.LineString(polygon)
point = geometry.Point(Point_X, Point_Y)
polygon = geometry.Polygon(line)

print(polygon.contains(point))

输出

True

见https://shapely.readthedocs.io/en/latest/manual.html

使用 shapely 指向多边形？

Point in polygon using shapely?

python

matlab

matplotlib

shapely