python 根据三点坐标计算夹角 角度 angle - xd21303/Notebook GitHub Wiki

def cal_ang(point_1, point_2, point_3):
    """
    根据三点坐标计算夹角
    :param point_1: 点1坐标
    :param point_2: 点2坐标
    :param point_3: 点3坐标
    :return: 返回任意角的夹角值，这里只是返回点2的夹角
    """
    a = math.sqrt((point_2[0] - point_3[0]) * (point_2[0] - point_3[0]) +
                  (point_2[1] - point_3[1]) * (point_2[1] - point_3[1]))
    b = math.sqrt((point_1[0] - point_3[0]) * (point_1[0] - point_3[0]) +
                  (point_1[1] - point_3[1]) * (point_1[1] - point_3[1]))
    c = math.sqrt((point_1[0] - point_2[0]) * (point_1[0] - point_2[0]) +
                  (point_1[1] - point_2[1]) * (point_1[1] - point_2[1]))
#     A = math.degrees(math.acos((a * a - b * b - c * c) / (-2 * b * c)))
    B = math.degrees(math.acos((b * b - a * a - c * c) / (-2 * a * c)))
#     C = math.degrees(math.acos((c * c - a * a - b * b) / (-2 * a * b)))
    if B > 90:
        B = 180 - B
#     print(B)
    d1 = distance.distance(point_1, point_2).m
#     print(d1)
    x = math.sin(math.radians(B)) * d1
#     print(x)
    return x