from __future__ import division import numpy as np from numpy import pi, cos, sin, sqrt, outer, ones import matplotlib.pyplot as plt from mpl_toolkits.mplot3d import Axes3D  fig = plt.figure(figsize=(10, 10)) ax = fig.add_subplot(111, projection='3d') u = np.linspace(0, 2 * pi, 100) v = np.linspace(0, pi, 100) one_v = ones(100)   # Sphere x1 = 10 * outer(cos(u), sin(v)) y1 = 10 * outer(sin(u), sin(v)) + 17 z1 = 10 * outer(one_v, np.cos(v)) ax.plot_surface(x1, y1, z1, rstride=5, cstride=5, cmap='Spectral',                 linewidth=0.5)  # Cylinder x2 = 6 * outer(cos(u), one_v) y2 = 6 * outer(sin(u), one_v) z2 = 20 * outer(one_v, v/pi - 0.5) ax.plot_surface(x2, y2, z2, rstride=5, cstride=5, cmap='Spectral',                 linewidth=0.5)  # Hyperboloid v = 2*v/pi - 1 x3 = 6 * outer(cos(u), sqrt(1 + v**2)) y3 = 6 * outer(sin(u), sqrt(1 + v**2)) - 16 z3 = 12 * outer(one_v, v) ax.plot_surface(x3, y3, z3, rstride=5, cstride=5, cmap='Spectral',                 linewidth=0.5)  # Fix aspect ratio and axes details ax.set_xlim(-13, 13) ax.set_ylim(-13, 13) ax.set_zlim(-13, 13) ax.view_init(elev=35, azim=-45) plt.axis('off') plt.savefig('Gaussian curvature.svg', transparent=True) plt.show()