用于matplotlib plot_surface命令的Colorbar

Question

我已经在Paul的帮助下为我的应用程序修改了mplot3d example code。代码如下：

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')

u = np.linspace(0, 2 * np.pi, 100)
v = np.linspace(0, np.pi, 100)

x = 10 * np.outer(np.cos(u), np.sin(v))
y = 10 * np.outer(np.sin(u), np.sin(v))
z = 10 * np.outer(np.ones(np.size(u)), np.cos(v))
z1 = z * np.cos(0.5*x)

N = z1 / z1.max()  # normalize 0..1
surf = ax.plot_surface(x, y, z, rstride=1, cstride=1, facecolors=cm.jet(N), linewidth=0, antialiased=False, shade=False)

fig.colorbar(surf, shrink=0.5, aspect=5)
plt.show()

该代码非常适合绘制曲面。但是当我尝试在上面的图中添加一个颜色条时，我收到以下错误：

Traceback (most recent call last):
  File "<ipython console>", line 1, in <module>
  File "C:\Python26\lib\site-packages\spyderlib\widgets\externalshell\startup.py", line 122, in runfile
    execfile(filename, glbs)
 File "C:\Documents and Settings\mramacha\My Documents\Python\Candela\test.py", line 22, in <module>
    fig.colorbar(surf, shrink=0.5, aspect=5)
  File "C:\Python26\lib\site-packages\matplotlib\figure.py", line 1104, in colorbar
    cb = cbar.Colorbar(cax, mappable, **kw)
  File "C:\Python26\lib\site-packages\matplotlib\colorbar.py", line 706, in __init__
    mappable.autoscale_None() # Ensure mappable.norm.vmin, vmax
  File "C:\Python26\lib\site-packages\matplotlib\cm.py", line 261, in autoscale_None
    raise TypeError('You must first set_array for mappable')
TypeError: You must first set_array for mappable

如果有人能够指导我，我将非常感激。

帕布

Answer 1

您可以使用代理可映射对象，因为未映射曲面阵列。 mappable只是将任何数组的值转换为由colormap定义的RGB颜色。

在您的情况下，您希望使用z1数组执行此操作：

import matplotlib.cm as cm
m = cm.ScalarMappable(cmap=cm.jet)
m.set_array(z1)
plt.colorbar(m)