"""
==================================================
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)

ax.contour(X, Y, Z, cmap=cm.coolwarm)  # Plot contour curves

plt.show()