如何在matplotlib中绘制受数据点限制的网格？

import matplotlib.pyplot as plt
import numpy as np

x = np.random.rand(100)
y = np.random.rand(100)
z = np.sin(x**2 + y**2)

xi = np.linspace(min(x), max(x), 100)
yi = np.linspace(min(y), max(y), 100)
xi, yi = np.meshgrid(xi, yi)

zi = griddata((x, y), z, (xi, yi), method='linear')

plt.tricontour(xi.flatten(), yi.flatten(), zi.flatten(), levels=10, linewidths=0.5, colors='k')
plt.tricontourf(xi.flatten(), yi.flatten(), zi.flatten(), levels=10, cmap='RdYlBu')
plt.colorbar()
plt.scatter(x, y, c=z, cmap='RdYlBu')
plt.xlabel('X')
plt.ylabel('Y')
plt.title('Contour Plot')
plt.show()