Wrong colorbar-ticks in imshow-colorbar with 10 colors

Hi all,

I want to use imshow to plot an array of floats using interpolation=‘nearest’ so that every gridbox has a distinct color. Also I want to limit the number of colors to a rather small number, e.g. 10. The problem is that the tick labels are not at the edge of each color in the colorbar, but somewhere in between.

An example is the trunk/matplotlib/examples/poormans_contour.py which does not work in my case.

from pylab import *

delta = 0.01
x = arange(-3.0, 3.0, delta)
y = arange(-3.0, 3.0, delta)
X,Y = meshgrid(x, y)
Z1 = bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)
Z2 = bivariate_normal(X, Y, 1.5, 0.5, 1, 1)
Z = Z2 - Z1 # difference of Gaussians

cmap = cm.get_cmap(‘jet’, 10) # 10 discrete colors

im = imshow(Z, cmap=cmap, interpolation=‘bilinear’)

Is there a solution?

Ciao Claas