| """ | |
| ================================= | |
| 3D surface with polar coordinates | |
| ================================= | |
| Demonstrates plotting a surface defined in polar coordinates. | |
| Uses the reversed version of the YlGnBu colormap. | |
| Also demonstrates writing axis labels with latex math mode. | |
| Example contributed by Armin Moser. | |
| """ | |
| import matplotlib.pyplot as plt | |
| import numpy as np | |
| fig = plt.figure() | |
| ax = fig.add_subplot(projection='3d') | |
| # Create the mesh in polar coordinates and compute corresponding Z. | |
| r = np.linspace(0, 1.25, 50) | |
| p = np.linspace(0, 2*np.pi, 50) | |
| R, P = np.meshgrid(r, p) | |
| Z = ((R**2 - 1)**2) | |
| # Express the mesh in the cartesian system. | |
| X, Y = R*np.cos(P), R*np.sin(P) | |
| # Plot the surface. | |
| ax.plot_surface(X, Y, Z, cmap=plt.cm.YlGnBu_r) | |
| # Tweak the limits and add latex math labels. | |
| ax.set_zlim(0, 1) | |
| ax.set_xlabel(r'$\phi_\mathrm{real}$') | |
| ax.set_ylabel(r'$\phi_\mathrm{im}$') | |
| ax.set_zlabel(r'$V(\phi)$') | |
| plt.show() | |