how show values *decreasing* up the y-axis like in a pcolor plot?

Hi -

   However, if you interact with the window (zoom in) than this
information is lost. It would be nice to be able to set a permanant
attritute for the axis, yaxis.reversed = True, or some such thing.



ylim(ymax, ymin)
xlim(xmax, xmin)

See, for example,