Demonstrates plotting contour (level) curves in 3D

This is like a contour plot in 2D except that the f(x, y)=c curve is plotted on the plane z=c.

from mpl_toolkits.mplot3d import axes3d
import matplotlib.pyplot as plt
from matplotlib import cm

ax = plt.figure().add_subplot(projection='3d')
X, Y, Z = axes3d.get_test_data(0.05)

cset = ax.contour(X, Y, Z, cmap=cm.coolwarm)  # Plot contour curves
ax.clabel(cset, fontsize=9, inline=True)

plt.show()