I found that
def set_sort_zpos(self,val):
'''Set the position to use for z-sorting.'''
self._sort_zpos = val
was missing from
class Line3DCollection(LineCollection) (in matplotlib 1.0.1):
Now, with the above method added, add_collection3d works as it should with line segments, and the following will work as expected 
'''
Purpose: Waterfall plot using LineCollection
Author: V.P.S. (2011-03-26)
'''
from mpl_toolkits.mplot3d import Axes3D
from matplotlib.collections import LineCollection
from matplotlib.colors import colorConverter
import matplotlib.pyplot as plt
import numpy as np
np.random.seed(40040157) # Used to allow repeatable experiments (plots)
fig = plt.figure()
ax = fig.gca(projection='3d')
cc = [colorConverter.to_rgba(c,alpha=0.6) for c in ('r','g','b','c','y','m','k')]
ncc = len(cc)
nxs = 5 # Num of points to connect (nxs-1 line segments)
# Generate X values
xs = np.arange(1, nxs+1, 1)
# Create array of Y values (to be updated)
ys = np.zeros(nxs)
# Create list of Z values
nzs = 4 # Num of Z-planes
zs = [zs+1 for zs in range(nzs)]
# Create list of colors (cyclic) for lines
colorlist = [cc[j%ncc] for j in range(nzs)]
segs = []
# Generate line segments in each Z-plane
for j in zs:
ys = np.random.rand(nxs)
segs.append(zip(xs, ys))
curves = LineCollection(segs, colors = colorlist)
ax.add_collection3d(curves, zs=zs, zdir='y')
ax.set_xlabel('X') # points to right -- X
ax.set_xlim3d(0, nxs+1)
ax.set_ylabel('Y') # points into screen -- Y
ax.set_ylim3d(0, nzs+1)
ax.set_zlabel('Z') # points up -- Z
ax.set_zlim3d(0, 1)
plt.show()
Have a Good Day
--V
