查找叉积在MatplotLib中查找直线上方/下方的点

import numpy as np
import matplotlib.pyplot as plt

start_point = np.array([x1, y1])
end_point = np.array([x2, y2])

direction_vector = end_point - start_point

normal_vector = np.array([-direction_vector[1], direction_vector[0]])

offset = 1.0  # 偏移量，可以根据实际情况调整
above_point = start_point + offset * normal_vector

plt.plot([start_point[0], end_point[0]], [start_point[1], end_point[1]], 'r-', label='Line')
plt.plot(start_point[0], start_point[1], 'bo', label='Start Point')
plt.plot(end_point[0], end_point[1], 'bo', label='End Point')
plt.plot(above_point[0], above_point[1], 'go', label='Above Point')
plt.xlabel('X')
plt.ylabel('Y')
plt.legend()
plt.show()