Reputation: 13
I would like to make a 3D plot with several 2D line plot "slices" and shade the area between the x-axis and the curve (i.e. under the curve). When trying to do this with polygons I am getting filling but the correct areas are not being filled. Any help would be most appreciated!
%matplotlib notebook
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.collections import PolyCollection
from mpl_toolkits.mplot3d import Axes3D
fig = plt.figure(figsize=(15,15))
ax = fig.add_subplot(111, projection='3d')
colors = ['r','b','g','m']
phi = [0,np.pi/4,np.pi/3, np.pi/2]
for c, k in zip(colors, phi):
eps2 = 0.001j
eps = np.linspace(-3,3,10000)
E = eps + eps2
gR = ((1-(((np.cos(k)+np.sin(k)*1j)**2)/((E+np.sqrt(1-E**2)*1j)**4)))/(1+(((np.cos(k)+np.sin(k)*1j)**2)/((E+np.sqrt(1-E**2)*1j)**4))))*1j
N = gR.imag
utol = 2
N[N>utol] = 2
ax.plot(eps, N, k,zdir='y', color=c)
verts = [list(zip(eps,N))]
poly = PolyCollection(verts, facecolors=c)
poly.set_alpha(1)
ax.add_collection3d(poly, zs=k,zdir='y')
ax.set_xlabel('Energy')
ax.set_ylabel('Phi')
ax.set_zlabel('DOS')
ax.set_yticks(phi)
ax.set_zlim(0,2)
ax.set_ylim(0,2)
plt.show()
Incorrect Plot for reference:
Upvotes: 1
Views: 740
Reputation: 80409
You created a polygon by connecting the first and last vertex of your curves. As these vertices have y = 2
everything gets connected with the horizontal line at that y-value.
To close the polygon at zero, repeat the first and the last x-value (np.pad(eps, 1, mode='edge')
) and pad the y-values with a zero at both ends (np.pad(N, 1)
).
If desired, ax.set_yticklabels(...)
can show the y-ticks as a formula with pi.
Further, matplotlib seems to have a serious problem about deciding the relative depth of each polygon, showing them all mixed up. A workaround could be to rotate everything 180 degrees, e.g. by setting ax.view_init(elev=22, azim=130)
.
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.collections import PolyCollection
from mpl_toolkits.mplot3d import Axes3D
fig = plt.figure(figsize=(15, 15))
ax = fig.add_subplot(111, projection='3d')
colors = ['r', 'b', 'g', 'm']
phi = [0, np.pi / 4, np.pi / 3, np.pi / 2]
for c, k in zip(colors, phi):
eps2 = 0.001j
eps = np.linspace(-3, 3, 10000)
E = eps + eps2
gR = ((1 - (((np.cos(k) + np.sin(k) * 1j) ** 2) / ((E + np.sqrt(1 - E ** 2) * 1j) ** 4))) / (
1 + (((np.cos(k) + np.sin(k) * 1j) ** 2) / ((E + np.sqrt(1 - E ** 2) * 1j) ** 4)))) * 1j
N = gR.imag
utol = 2
N[N > utol] = 2
ax.plot(eps, N, k, zdir='y', color=c)
verts = [list(zip(np.pad(eps, 1, mode='edge'), np.pad(N, 1)))]
poly = PolyCollection(verts, facecolors=c)
poly.set_alpha(1)
ax.add_collection3d(poly, zs=k, zdir='y')
ax.set_xlabel('Energy')
ax.set_ylabel('Phi')
ax.set_zlabel('DOS')
ax.set_yticks(phi)
ax.set_yticklabels(['$0$' if k == 0 else f'$\pi / {np.pi / k:.0f}$' for k in phi])
ax.set_zlim(0, 2)
ax.set_ylim(0, 2)
ax.view_init(elev=22, azim=130)
plt.show()
Upvotes: 1