For drawing just the arrow, there is an easier method:-
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
fig = plt.figure()
ax = fig.gca(projection='3d')
ax.set_aspect("equal")
#draw the arrow
ax.quiver(0,0,0,1,1,1,length=1.0)
plt.show()
quiver can actually be used to plot multiple vectors at one go. The usage is as follows:- [ from http://matplotlib.org/mpl_toolkits/mplot3d/tutorial.html?highlight=quiver#mpl_toolkits.mplot3d.Axes3D.quiver]
quiver(X, Y, Z, U, V, W, **kwargs)
Arguments:
X, Y, Z: The x, y and z coordinates of the arrow locations
U, V, W: The x, y and z components of the arrow vectors
The arguments could be array-like or scalars.
Keyword arguments:
length: [1.0 | float] The length of each quiver, default to 1.0, the unit is the same with the axes
arrow_length_ratio: [0.3 | float] The ratio of the arrow head with respect to the quiver, default to 0.3
pivot: [ ‘tail’ | ‘middle’ | ‘tip’ ] The part of the arrow that is at the grid point; the arrow rotates about this point, hence the name pivot. Default is ‘tail’
normalize: [False | True] When True, all of the arrows will be the same length. This defaults to False, where the arrows will be different lengths depending on the values of u,v,w.