Vertically fill 3d matplotlib plot

Question

I have a 3d plot made using matplotlib. I now want to fill the vertical space between the drawn line and the x,y axis to highlight the height of the line on the z axis. On a

Answer 1

You're right. It seems that there is no equivalent in 3D plot for the 2D plot function fill_between. The solution I propose is to convert your data in 3D polygons. Here is the corresponding code:

import math as mt
import matplotlib.pyplot as pl
import numpy as np
import random as rd

from mpl_toolkits.mplot3d import Axes3D
from mpl_toolkits.mplot3d.art3d import Poly3DCollection


# Parameter (reference height)
h = 0.0

# Code to generate the data
n = 200
alpha = 0.75 * mt.pi
theta = [alpha + 2.0 * mt.pi * (float(k) / float(n)) for k in range(0, n + 1)]
xs = [1.0 * mt.cos(k) for k in theta]
ys = [1.0 * mt.sin(k) for k in theta]
zs = [abs(k - alpha - mt.pi) * rd.random() for k in theta]

# Code to convert data in 3D polygons
v = []
for k in range(0, len(xs) - 1):
    x = [xs[k], xs[k+1], xs[k+1], xs[k]]
    y = [ys[k], ys[k+1], ys[k+1], ys[k]]
    z = [zs[k], zs[k+1],       h,     h]
    #list is necessary in python 3/remove for python 2
    v.append(list(zip(x, y, z))) 
poly3dCollection = Poly3DCollection(v)

# Code to plot the 3D polygons
fig = pl.figure()
ax = Axes3D(fig)
ax.add_collection3d(poly3dCollection)
ax.set_xlim([min(xs), max(xs)])
ax.set_ylim([min(ys), max(ys)])
ax.set_zlim([min(zs), max(zs)])
ax.set_xlabel("x")
ax.set_ylabel("y")
ax.set_zlabel("z")

pl.show()

It produces the following figure:

I hope this will help you.