# 3D-vectorveld import matplotlib.pyplot as plt import numpy as np x, y, z = np.meshgrid (np.arange (-1, 1, 0.25), np.arange (-1, 1, 0.25), np.arange (-1, 1, 0.25)) u = 2 * x * y + z v = x**2 + 2 * z**2 w = 4 * y * z - x plt.figure (figsize = (8, 8)) ax = plt.axes (projection = "3d") q = ax.quiver (x, y, z, u, v, w, color = "brown", length = 0.15) plt.show ()