0. 前言

python 求直线与多边形交点并显示

1. 正文

1.1 步骤

python 复制代码

import matplotlib.pyplot as plt
from shapely.geometry import LineString, Polygon

导入所需的模块和函数：

python 复制代码

import matplotlib.pyplot as plt
from shapely.geometry import LineString, Polygon

创建直线对象和多边形对象：

python 复制代码

line = LineString([(x1, y1), (x2, y2)])
polygon = Polygon([(x3, y3), (x4, y4), ..., (xn, yn)])

提取多边形的边界作为LineString对象：

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boundary = polygon.boundary

计算直线与多边形边界的交点：

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intersection = line.intersection(boundary)

将交点转换为MultiPoint对象（如果有多个交点）或Point对象（如果只有一个交点）：

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if intersection.geom_type == 'MultiPoint':
    intersection_points = list(intersection)
else:
    intersection_points = [intersection]

绘制多边形、直线和交点

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fig, ax = plt.subplots()
ax.plot(*boundary.xy, label='Polygon')
ax.plot(*line.xy, label='Line')

for point in intersection_points:
    ax.plot(*point.xy, 'ro', label='Intersection')

ax.legend()
plt.show()

1.2 完整代码

python 复制代码

import matplotlib.pyplot as plt
from shapely.geometry import LineString, Polygon

# 创建直线对象和多边形对象
line = LineString([(0, 0), (3, 5)])
polygon = Polygon([(1, 1), (1, 4), (4, 4), (4, 1)])

# 提取直线的起点和终点坐标以及多边形的边界坐标
line_coords = line.xy
boundary_coords = polygon.boundary.xy

# 计算直线与多边形边界的交点
boundary = polygon.boundary
intersection = line.intersection(boundary)

if intersection.geom_type == 'MultiPoint':
    intersection_points = list(intersection)
else:
    intersection_points = [intersection]

fig, ax = plt.subplots()
ax.plot(*boundary.xy, label='Polygon')
ax.plot(*line.xy, label='Line')

for point in intersection_points:
    ax.plot(*point.xy, 'ro', label='Intersection')

ax.legend()
plt.show()