Douglas-Peucker算法 Python代码

以下是Douglas-Peucker算法的Python代码实现：

import math

def point_line_distance(point, start, end):
    """
    计算点到直线的距离
    """
    x = point[0]
    y = point[1]
    x1 = start[0]
    y1 = start[1]
    x2 = end[0]
    y2 = end[1]
    numerator = abs((y2-y1)*x - (x2-x1)*y + x2*y1 - y2*x1)
    denominator = math.sqrt((y2-y1)**2 + (x2-x1)**2)
    distance = numerator / denominator
    return distance

def douglas_peucker(points, epsilon):
    """
    Douglas-Peucker算法
    """
    dmax = 0
    index = 0
    end = len(points) - 1
    for i in range(1, end):
        d = point_line_distance(points[i], points[0], points[end])
        if d > dmax:
            index = i
            dmax = d
    if dmax > epsilon:
        new_points_left = douglas_peucker(points[:index+1], epsilon)
        new_points_right = douglas_peucker(points[index:], epsilon)
        new_points = new_points_left[:-1] + new_points_right
    else:
        new_points = [points[0], points[end]]
    return new_points

其中，point_line_distance函数用于计算点到直线的距离，douglas_peucker函数是Douglas-Peucker算法的实现函数，points是输入的点集，epsilon是控制精度的参数。函数返回经过简化后的点集。