| """ | |
| ============== | |
| 3D quiver plot | |
| ============== | |
| Demonstrates plotting directional arrows at points on a 3D meshgrid. | |
| """ | |
| import matplotlib.pyplot as plt | |
| import numpy as np | |
| ax = plt.figure().add_subplot(projection='3d') | |
| # Make the grid | |
| x, y, z = np.meshgrid(np.arange(-0.8, 1, 0.2), | |
| np.arange(-0.8, 1, 0.2), | |
| np.arange(-0.8, 1, 0.8)) | |
| # Make the direction data for the arrows | |
| u = np.sin(np.pi * x) * np.cos(np.pi * y) * np.cos(np.pi * z) | |
| v = -np.cos(np.pi * x) * np.sin(np.pi * y) * np.cos(np.pi * z) | |
| w = (np.sqrt(2.0 / 3.0) * np.cos(np.pi * x) * np.cos(np.pi * y) * | |
| np.sin(np.pi * z)) | |
| ax.quiver(x, y, z, u, v, w, length=0.1, normalize=True) | |
| plt.show() | |