具有表面梯度的颜色 matplotlibplot_surface 命令

我想将 surf 命令从MATLAB到plot_surface命令中绘图库.

我面临的挑战是使用时cmapplot_surface 命令中的函数用渐变为表面着色。

这里是matlab script

% Matlab Commands
x = -5:.25:5; y = x
[x,y] = meshgrid(x);
R = sqrt(x.^2 + y.^2);
Z = sin(R)
surf(x,y,Z,gradient(Z))

可以在此处找到来自此类命令的图。(http://www.mathworks.com/help/techdoc/visualize/f0-18164.html#f0-46458) http://www.mathworks.com/help/techdoc/visualize/f0-18164.html#f0-46458

这里是python脚本 当使用 python 和 matplotlib 创建类似的函数时，我无法使用渐变为表面着色。

# Python-matplotlib Commands
from mpl_toolkits.mplot3d import Axes3D
from matplotlib import cm
import matplotlib.pyplot as plt
import numpy as np

fig = plt.figure()
ax = fig.gca(projection='3d')
X = np.arange(-5, 5, 0.25)
Y = np.arange(-5, 5, 0.25)
X, Y = np.meshgrid(X, Y)
R = np.sqrt(X**2 + Y**2)
Z = np.sin(R)
surf = ax.plot_surface(X, Y, Z, rstride=1, cstride=1, cmap=gradient(Z), linewidth=0, antialiased=False)
plt.show()

我收到以下错误消息：

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\tmp.py", line 13, in <module>
    surf = ax.plot_surface(X, Y, Z, rstride=1, cstride=1, cmap=gradient(Z), linewidth=0, antialiased=False)
  File "C:\Python26\lib\site-packages\mpl_toolkits\mplot3d\axes3d.py", line 729, in plot_surface
    polyc = art3d.Poly3DCollection(polys, *args, **kwargs)
  File "C:\Python26\lib\site-packages\mpl_toolkits\mplot3d\art3d.py", line 344, in __init__
    PolyCollection.__init__(self, verts, *args, **kwargs)
  File "C:\Python26\lib\site-packages\matplotlib\collections.py", line 570, in __init__
    Collection.__init__(self,**kwargs)
  File "C:\Python26\lib\site-packages\matplotlib\collections.py", line 86, in __init__
    cm.ScalarMappable.__init__(self, norm, cmap)
  File "C:\Python26\lib\site-packages\matplotlib\cm.py", line 155, in __init__
    self.cmap = get_cmap(cmap)
  File "C:\Python26\lib\site-packages\matplotlib\cm.py", line 126, in get_cmap
    if name in cmap_d:
TypeError: unhashable type: 'list'

任何输入都会有帮助。

Praboo

首先，看起来您想要从梯度幅度映射颜色。您正在尝试使用梯度向量，这就是您收到“列表”错误的原因。

其次，您可以提供 cmap，但它仅定义您希望如何将 Z 值映射到颜色。如果您想要新的脸部颜色，请使用facecolors争论 http://matplotlib.sourceforge.net/mpl_toolkits/mplot3d/tutorial.html#surface-plots.

第三，您需要将值标准化为 0..1，然后通过颜色图映射它们。 （我认为还有另一种方法，但是将幅度除以最大值非常简单）

这是代码：

# Python-matplotlib Commands
from mpl_toolkits.mplot3d import Axes3D
from matplotlib import cm
import matplotlib.pyplot as plt
import numpy as np

fig = plt.figure()
ax = fig.gca(projection='3d')
X = np.arange(-5, 5, .25)
Y = np.arange(-5, 5, .25)
X, Y = np.meshgrid(X, Y)
R = np.sqrt(X**2 + Y**2)
Z = np.sin(R)
Gx, Gy = np.gradient(Z) # gradients with respect to x and y
G = (Gx**2+Gy**2)**.5  # gradient magnitude
N = G/G.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)
plt.show()

结果：