code: def image_set_clim(zmin=None, zmax=None, axes="gca"):
      
      if axes=="gca": axes=_pylab.gca()
  
      image = axes.images[0]
  
      if zmin=='auto': zmin = _n.min(image.get_array())
      if zmax=='auto': zmax = _n.max(image.get_array())
  
      if zmin==None: zmin = image.get_clim()[0]
      if zmax==None: zmax = image.get_clim()[1]
  
      image.set_clim(zmin, zmax)
  
      _pylab.draw()
docs: This will set the clim (range) of the colorbar.
  
      Setting zmin or zmax to None will not change them.
      Setting zmin or zmax to "auto" will auto-scale them to include all the data.