Hi,
Here is an example to report a small bug in colorbars: ticks outside the "boundaries" doesn't display. "Boundaries" doesn't matter, only "values" do (cf example). It appends only when values and boundaries are differents (usefull for what I'm doing).
import scipy
from matplotlib import pyplot
pyplot.imshow(scipy.lena())
cbar_boundaries = scipy.linspace(-1000,1000,100)
cbar_values = scipy.linspace(0,255,99)
cb = pyplot.colorbar(boundaries=cbar_boundaries, values=cbar_values)
cb.set_ticks([-500, 50, 500])
pyplot.show()
Cheers,
Benoît