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

fig = plt.figure()
ax = Axes3D(fig, azim = -128, elev = 52)
X = np.arange(-2, 2, 0.1)
Y = np.arange(-2,2, 0.1)
X, Y = np.meshgrid(X, Y)
Z = 100*(Y-X**2)**2+(1-X)**2
ax.plot_surface(X, Y, Z, rstride = 1, cstride = 1, norm = LogNorm(), cmap = cm.jet)
plt.xlabel("x")
plt.ylabel("y")
plt.title("Rosenbrock’s valley")

plt.savefig("Rosenbrock’s valley.PNG")

plt.show()