bar3d图的色彩图/颜色问题

Question

我已经编写了一些代码来绘制英国城镇/城市的经度和纬度，其中3D条形高度代表了这些地方的人口。我也尝试使用色彩图对条形码进行颜色编码，以便更容易看到人口的变化。但是，我的代码似乎没有遵循colormap，而是所有的栏都有非常相似的颜色 - 我不知道我哪里出错了

from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
import numpy as np

pop = [189120, 91297, 107123, 107355, 94782, 87590, 142968, 1085810, 117963, 147663, 194189, 187503, 349561, 229700, 535907, 145818, 335145, 110507, 116447, 86011, 88483, 119441, 325949, 106943, 92363, 255394, 109805, 144170, 109185, 468720, 113507, 120046, 104157, 589900, 136362, 88243, 88134, 88855, 91053, 94932, 120256, 162949, 284321, 144957, 474632, 443760, 100160, 552267, 8173941, 211228, 107627, 510746, 174700, 171750, 268064, 128060, 215173, 186682, 289301, 86552, 96555, 159994, 161707, 234982, 154718, 238137, 97886, 95580, 218705, 107926, 109691, 134022, 103886, 518090, 155298, 123187, 253651, 175547, 91703, 102885, 89663, 105878, 270726, 174286, 109015, 179485, 182441, 142723, 99251, 165456, 131982, 91930, 218791, 83641, 103608, 105367, 265178, 100153, 109120, 152841]

lat = [57.14369, 53.55, 51.56844, 51.26249, 51.37795, 52.13459, 53.39337, 52.48142, 53.75, 53.81667, 53.58333, 50.72048, 53.79391, 50.82838, 51.45523, 52.2, 51.48, 51.73575, 51.9, 53.1905, 53.25, 51.88921, 52.40656, 51.11303, 54.52429, 52.92277, 53.52327, 56.5, 50.76871, 55.95206, 50.7236, 54.96209, 51.38914, 55.86515, 51.86568, 53.56539, 53.71667, 54.68611, 50.85519, 51.75369, 51.62907, 53.64904, 53.7446, 52.05917, 53.79648, 52.6386, 53.22683, 53.41058, 51.50853, 51.87967, 51.26667, 53.48095, 54.57623, 52.04172, 54.97328, 51.58774, 52.25, 52.62783, 52.9536, 52.52323, 53.54051, 51.75222, 52.57364, 50.37153, 50.71667, 50.79899, 53.76667, 51.58571, 51.45625, 53.61766, 53.43012, 53.42519, 53.48771, 53.38297, 51.50949, 52.41426, 50.90395, 51.53782, 53.64779, 53.45, 51.90224, 53.40979, 53.00415, 54.90465, 52.56667, 51.62079, 51.55797, 52.67659, 53.68331, 53.39254, 51.65531, 52.51868, 51.50853, 51.34603, 53.53333, 51.31903, 52.58547, 52.18935, 50.81448, 53.95763]

long = [-2.09814, -1.48333, 0.45782, -1.08708, -2.35907, -0.46632, -3.01479, -1.89983, -2.48333, -3.05, -2.43333, -1.8795, -1.75206, -0.13947, -2.59665, 0.11667, -3.18, 0.46958, -2.08333, -2.89189, -1.41667, 0.90421, -1.51217, -0.18312, -1.55039, -1.47663, -1.13691, -2.96667, 0.28453, -3.19648, -3.52751, -1.60168, 0.54863, -4.25763, -2.2431, -0.07553, -1.85, -1.2125, 0.57292, -0.47517, -0.74934, -1.78416, -0.33525, 1.15545, -1.54785, -1.13169, -0.53792, -2.97794, -0.12574, -0.41748, 0.51667, -2.23743, -1.23483, -0.75583, -1.61396, -2.99835, -0.88333, 1.29834, -1.15047, -1.46523, -2.1183, -1.25596, -0.24777, -4.14305, -2.0, -1.09125, -2.71667, 0.60459, -0.97113, -2.1552, -1.35678, -2.32443, -2.29042, -1.4659, -0.59541, -1.78094, -1.40428, 0.71433, -3.00648, -2.73333, -0.20256, -2.15761, -2.18538, -1.38222, -1.81667, -3.94323, -1.78116, -2.44926, -1.49768, -2.58024, -0.39602, -1.9945, -0.12574, -2.97665, -2.61667, -0.55893, -2.12296, -2.22001, -0.37126, -1.08271]


fig = plt.figure()
ax = Axes3D(fig)

X,Y,Z = np.array(long),np.array(lat),np.log10(np.array(pop))

colours = plt.cm.rainbow_r(Z/np.log10(max(pop)))

plot1 = ax.bar3d(X,Y,Z,dx=0.2,dy=0.2,dz=Z/3,color=colours)
ax.set_xlabel('\nLongitude (\u00B0)')
ax.set_ylabel('\nLatitude (\u00B0)')
ax.set_zlabel('\nlog\u2081\u2080(Population)')
ax.set_zlim3d(4,7)
ax.view_init(elev=70,azim=280)


colourMap = plt.cm.ScalarMappable(cmap=plt.cm.rainbow_r)
colourMap.set_array(Z)
colBar = plt.colorbar(colourMap).set_label('log\u2081\u2080(Population)')

plt.show()

代码生成此图：

我认为大多数酒吧应该是红色/橙色，只有主要城市是黄色/绿色/蓝色......

Answer 1

(Z/np.log10(max(pop))).min()是0.7。因此，所有值都确实在色彩映射的上限范围内。

您可能希望在将数据提供给色彩映射之前对其进行规范化：

norm = plt.Normalize((Z/np.log10(max(pop))).min(), (Z/np.log10(max(pop))).max())
colours = plt.cm.rainbow_r(norm(Z/np.log10(max(pop))))