Matplotlib: arrows
Some example code for how to plot an arrow using the Arrow function.
from matplotlib.pyplot import *
from numpy import *
x = arange(10)
y = x
# Plot junk and then a filled region
plot(x, y)
# Now lets make an arrow object
arr = Arrow(2, 2, 1, 1, edgecolor='white')
# Get the subplot that we are currently working on
ax = gca()
# Now add the arrow
ax.add_patch(arr)
# We should be able to make modifications to the arrow.
# Lets make it green.
arr.set_facecolor('g')