old_contents: # example showing how to plot scattered data with hexbin.
  from numpy.random import uniform
  import matplotlib.pyplot as plt
  import numpy as np
  from mpl_toolkits.basemap import Basemap
  
  # create north polar stereographic basemap
  m = Basemap(lon_0=270, boundinglat=20, projection='npstere',round=True)
  
  # number of points to plot.
  npts = 10000
  bins = 40
  # generate random points on a sphere,
  # so that every small area on the sphere is expected
  # to have the same number of points.
  # http://mathworld.wolfram.com/SpherePointPicking.html
  u = uniform(0.,1.,size=npts)
  v = uniform(0.,1.,size=npts)
  lons1 = 360.*u
  lats1 = (180./np.pi)*np.arccos(2*v-1) - 90.
  # toss points outside of map region.
  lats = np.compress(lats1 > 20, lats1)
  lons = np.compress(lats1 > 20, lons1)
  # convert to map projection coordinates.
  x, y = m(lons, lats)
  # function to plot at those points.
  xscaled = 4.*(x-0.5*(m.xmax-m.xmin))/m.xmax
  yscaled = 4.*(y-0.5*(m.ymax-m.ymin))/m.ymax
  z = xscaled*np.exp(-xscaled**2-yscaled**2)
  
  # make plot using hexbin
  fig = plt.figure(figsize=(12,5))
  ax = fig.add_subplot(121)
  CS = plt.hexbin(x,y,C=z,gridsize=bins,cmap=plt.cm.jet)
  # draw coastlines, lat/lon lines.
  m.drawcoastlines()
  m.drawparallels(np.arange(0,81,20))
  m.drawmeridians(np.arange(-180,181,60))
  m.colorbar() # draw colorbar
  plt.title('hexbin demo')
  
  # use histogram2d instead of hexbin.
  ax = fig.add_subplot(122)
  #m = Basemap(lon_0=270, boundinglat=20, projection='npstere',round=True)
  bincount, xedges, yedges = np.histogram2d(x, y, bins=bins)
  mask = bincount == 0
  # reset zero values to one to avoid divide-by-zero
  bincount = np.where(bincount == 0, 1, bincount)
  H, xedges, yedges = np.histogram2d(x, y, bins=bins, weights=z)
  H = np.ma.masked_where(mask, H/bincount)
  # set color of masked values to white (hexbin does this by default)
  palette = plt.cm.jet
  palette.set_bad('white', 1.0)
  CS = m.pcolormesh(xedges,yedges,H.T,shading='flat',cmap=palette)
  # draw coastlines, lat/lon lines.
  m.drawcoastlines()
  m.drawparallels(np.arange(0,81,20))
  m.drawmeridians(np.arange(-180,181,60))
  m.colorbar() # draw colorbar
  plt.title('histogram2d demo')
  
  plt.show()
  
new_contents: # example showing how to plot scattered data with hexbin.
  from numpy.random import uniform
  import matplotlib.pyplot as plt
  import numpy as np
  from mpl_toolkits.basemap import Basemap
  
  # create north polar stereographic basemap
  m = Basemap(lon_0=270, boundinglat=20, projection='npstere',round=True)
  
  # number of points to plot.
  npts = 10000
  bins = 40
  # generate random points on a sphere,
  # so that every small area on the sphere is expected
  # to have the same number of points.
  # http://mathworld.wolfram.com/SpherePointPicking.html
  u = uniform(0.,1.,size=npts)
  v = uniform(0.,1.,size=npts)
  lons1 = 360.*u
  lats1 = (180./np.pi)*np.arccos(2*v-1) - 90.
  # toss points outside of map region.
  lats = np.compress(lats1 > 20, lats1)
  lons = np.compress(lats1 > 20, lons1)
  # convert to map projection coordinates.
  x, y = m(lons, lats)
  # function to plot at those points.
  xscaled = 4.*(x-0.5*(m.xmax-m.xmin))/m.xmax
  yscaled = 4.*(y-0.5*(m.ymax-m.ymin))/m.ymax
  z = xscaled*np.exp(-xscaled**2-yscaled**2)
  
  # make plot using hexbin
  fig = plt.figure(figsize=(12,5))
  ax = fig.add_subplot(121)
  CS = plt.hexbin(x,y,C=z,gridsize=bins,cmap=plt.cm.jet)
  # draw coastlines, lat/lon lines.
  m.drawcoastlines()
  m.drawparallels(np.arange(0,81,20))
  m.drawmeridians(np.arange(-180,181,60))
  m.colorbar() # draw colorbar
  plt.title('hexbin demo')
  
  # use histogram2d instead of hexbin.
  ax = fig.add_subplot(122)
  bincount, xedges, yedges = np.histogram2d(x, y, bins=bins)
  mask = bincount == 0
  # reset zero values to one to avoid divide-by-zero
  bincount = np.where(bincount == 0, 1, bincount)
  H, xedges, yedges = np.histogram2d(x, y, bins=bins, weights=z)
  H = np.ma.masked_where(mask, H/bincount)
  # set color of masked values to white (hexbin does this by default)
  palette = plt.cm.jet
  palette.set_bad('white', 1.0)
  CS = m.pcolormesh(xedges,yedges,H.T,shading='flat',cmap=palette)
  # draw coastlines, lat/lon lines.
  m.drawcoastlines()
  m.drawparallels(np.arange(0,81,20))
  m.drawmeridians(np.arange(-180,181,60))
  m.colorbar() # draw colorbar
  plt.title('histogram2d demo')
  
  plt.show()
  
subject: remove dead code