I would like to have a secondary y-axis that has the same scale, but a
different label. Also, I would like to draw a dashed line down the
center of the plot.
I have used,
ax1 = pcolor(a, shading='flat', cmap=cm.gray_r)
and the scale is different for the second y-axis as well as prints on
top of the colorbar.
"The game of science can accurately be described as a never-ending
insult to human intelligence." - João Magueijo