python繪制三維條形圖_如何在matplotlib中建立三維條形圖的圖例？

您需要使用不支援圖例的proxy artist。

此代碼：from mpl_toolkits.mplot3d import Axes3D

import matplotlib.pyplot as plt

import numpy as np

fig = plt.figure()

ax = fig.add_subplot(111, projection='3d')

x, y = np.random.rand(2, 100) * 4

hist, xedges, yedges = np.histogram2d(x, y, bins=4)

elements = (len(xedges) - 1) * (len(yedges) - 1)

xpos, ypos = np.meshgrid(xedges[:-1]+0.25, yedges[:-1]+0.25)

xpos = xpos.flatten()

ypos = ypos.flatten()

zpos = np.zeros(elements)

dx = 0.5 * np.ones_like(zpos)

dy = dx.copy()

dz = hist.flatten()

ax.bar3d(xpos[:8], ypos[:8], zpos[:8], dx, dy, dz, color='b', zsort='average')

blue_proxy = plt.Rectangle((0, 0), 1, 1, fc="b")

ax.bar3d(xpos[8:], ypos[8:], zpos[8:], dx, dy, dz, color='r', zsort='average')

red_proxy = plt.Rectangle((0, 0), 1, 1, fc="r")

ax.legend([blue_proxy,red_proxy],['cars','bikes'])

plt.show()

産生這個：