##########
## Code for the figure
##########
"""This generates the graph of the function f(x, y) = sin(sqrt(x^2 + y^2))."""

import matplotlib.pyplot as plt
import numpy as np
from matplotlib import cm
from mpl_toolkits.mplot3d import Axes3D

fig = plt.figure()
fig.clf()
ax = fig.add_subplot(1, 1, 1, projection='3d')

x = np.arange(-5, 5, 0.25)
y = np.arange(-5, 5, 0.25)
X, Y = np.meshgrid(x, y)
R = np.sqrt(X*X + Y*Y)
Z = np.sin(R)

surf = ax.plot_surface(X, Y, Z, rstride=1, cstride=1, cmap=cm.coolwarm)

fig.savefig("matplotlib_3d.svg")
plt.show()
##########