Python matplotlib : plot3D with a color for 4D

Question

I am trying to make a 3D plot from x, y, z points list, and I want to plot color depending on the values of a fourth variable rho.

Currently I have ;

fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')
ax.plot3D(cell_x, cell_y, cell_z, linestyle='None', marker='o', markersize = 5, antialiased=True)
ax.set_xlim3d(0.45, 0.55)
ax.set_ylim3d(0.45, 0.55)
ax.set_zlim3d(0.45, 0.55)

How to add cell_rho (my fourth array) as the color of my x, y, z points ? (for example for a jet colormap).

Thank you very much.

EDIT : I can't use scatter plots because for my 18000 points scatter plots are very slow compared to plot3d with markers only.

Answer 1

If you want to display a simple 3D scatterplot, can't you just use scatter?
E.g.,

x, y, z = randn(100), randn(100), randn(100)
fig = plt.figure()
from mpl_toolkits.mplot3d import Axes3D
ax = fig.add_subplot(111, projection='3d')
ax.scatter(x, y, z, c=randn(100))
plt.show()

(I'm running the above code under python -pylab.)

It seems, on the contrary, that with plot3D you must convert your fourth dimension to RGB tuples.