三维图像
```python
# f1 score curve
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
import numpy as np
x = np.linspace(0.01, 1, 20)
y = np.linspace(0.01, 1, 20)
X, Y = np.meshgrid(x, y)
print(X)
print(Y)
Z = 2*X*Y/(X+Y)
fig = plt.figure()
ax = fig.gca(projection='3d')
ax.plot_surface(X, Y, Z, rstride=1, cstride=1, cmap='rainbow')
plt.show()
```
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