We will draw a filled contour plot of the three-dimensional mathematical function in the previous Time for action section. The code is also pretty similar. One key difference is that we don't need the 3D projection parameter any more. To draw the filled contour plot, use the following line of code:

ax.contourf(x, y, z)

This gives us the following filled contour plot:

import matplotlib.pyplot as plt
import numpy as np
from matplotlib import cm

fig = plt.figure()
ax = fig.add_subplot(111)

u = np.linspace(-1, 1, 100)

x, y = np.meshgrid(u, u)
z = x ** 2 + y ** 2
ax.contourf(x, y, z)

plt.show()