# 3D-vectorveld

import matplotlib.pyplot as plt
import numpy as np

rho, phi, theta = np.meshgrid (np.arange (0.1, 5, 0.5), np.arange (0, np.pi, 0.5), np.arange (0, 2 * np.pi, 0.5))

x = rho * np.cos (phi) * np.sin (theta)
y = rho * np.sin (phi) * np.sin (theta)
z = rho * np.cos (theta)

u = x / np.sqrt (x**2 + y**2 + z**2)
v = y / np.sqrt (x**2 + y**2 + z**2)
w = z / np.sqrt (x**2 + y**2 + z**2)

plt.figure (figsize = (8, 8))

ax = plt.axes (projection = "3d")

q = ax.quiver (x, y, z, u, v, w, color = "blue", length = 0.5)

plt.show ()