从mplot3d图形获取数据 [英] Get data from mplot3d graph

问题描述

我找不到如何从mplot3d图形中获取数据的方法.类似于2D样式:

I can’t find out how to get data from an mplot3d graph. Something similar to the 2D style:

line.get_xdata()

有可能吗?

推荐答案

Line3D

您可以从(私有)_verts3d属性获取原始数据

Line3D

You can get get the original data from the (private) _verts3d attribute

xdata, ydata, zdata = line._verts3d
print(xdata)

完整示例

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

mpl.rcParams['legend.fontsize'] = 10

fig = plt.figure()
ax = fig.gca(projection='3d')

# Prepare arrays x, y, z
x = np.arange(5)
y = np.arange(5)*4
z = np.arange(5)*100

line, = ax.plot(x, y, z, label='curve')

fig.canvas.draw()

xdata, ydata, zdata = line._verts3d
print(xdata)  # This prints [0 1 2 3 4]

plt.show()

---

一些解释:get_data或get_xdata的问题在于，绘制图形后它将返回投影坐标.因此，在绘制图形之前，line.get_xdata()确实会返回正确的值，而在绘制之后，它将返回类似

---

Some explanation: The problem with get_data or get_xdata is that it will return the projected coordinates once the figure is drawn. So while before drawing the figure, line.get_xdata() would indeed return the correct values, after drawing, it would return something like

[ -6.14413090e-02  -3.08824862e-02  -3.33066907e-17   3.12113190e-02 6.27567511e-02]

在上面的示例中，

是投影到2D上的3D坐标的x分量.

in the above example, which is the x component of the 3D coordinates projected onto 2D.

有一个向matplotlib发出拉动请求，该请求将允许获取数据通过方法get_data_3d.仍然没有合并，但是可以允许在不使用私有参数的情况下完成上述操作.

There is a pull request to matplotlib, which would allow to get the data via methods get_data_3d. This is still not merged, but might allow the above to be done without using private arguments in a future version of matplotlib.

对于plot_surface图，这看起来很相似，除了要查看的属性是._vec

For a plot_surface plot this looks similar, except that the attribute to look at is the ._vec

surf = ax.plot_surface(X, Y, Z)
xdata, ydata, zdata, _ = surf._vec
print(xdata)

这篇关于从mplot3d图形获取数据的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！