从三维轮廓线中提取数据

Question

我有一个三维的numpy数据数组，以及三个相关的数组，给出每个点的极坐标。我想生成一个给定值的等值面 原始数组，并提取该表面上的点的r，theta和phi值。在2D中我做了这个（部分遵循这里给出的建议）如下所示（这也找到了假设为椭圆体数据的长轴和短轴之间的r的百分比差异），但是matplotlib函数轮廓不起作用3D。任何人都可以建议一种方法吗？

def ellipsecalc（divret2real，r，theta）：

time_e1 = time.time()

plt.figure()
plt.contour(divret2real, [.8])
plt.show()

cs=plt.contour(divret2real, [.3])
p = cs.collections[0].get_paths()[0]           # from matplotlib 
v = p.vertices                                 # interplated x,y positions of the contour
x = v[:,0]
y = v[:,1]

time_e2 = time.time()
print ('time for r at fixed plotting', time_e2 - time_e1, 'seconds')


rellipse = ndimage.map_coordinates(r, [[x],[y]], order=1)
thellipse = ndimage.map_coordinates(theta, [[x],[y]], order=1)
rellipse1d = rellipse.flatten()
thellipse1d = thellipse.flatten()

plt.figure()
plt.plot(thellipse1d, rellipse1d)
plt.show()

rellmax = np.amax(rellipse1d)
rellmin = np.amin(rellipse1d)

percrdiff = (((rellmax - rellmin)/2.) / ((rellmax + rellmin)/2.)) * 100.

rmaxref = np.argmax(rellipse1d)
thofrmax = thellipse1d[rmaxref]

print ('percentage difference, max and min axes', percrdiff)

time_e3 = time.time()
print ('time for r at fixed ac calc', time_e3 - time_e2, 'seconds')

return percrdiff, rellipse1d, thellipse1d, thofrmax