title: python: scatter does not display
body: <p>I have some trouble using scatter in python. I have 2 vectors of size 100 of latitudes and longitudes, and a vector 100 of corresponding data of values between 1 and 2. </p>
  
  <p>I am trying to display these data on a north polar stereographic projected map, but nothing appears on the figure. Here is my code:</p>
  
  <pre><code>import numpy as np
  import matplotlib as mpl
  from matplotlib import pyplot as plt
  from matplotlib import colors as mpl_colors
  from mpl_toolkits.basemap import Basemap`
  
  lon=np.linspace(-180,180,num=100)
  
  
  lat=np.linspace(75,75,num=100)
  data=1+np.random.rand(100)
  
  cmap  =  plt.cm.jet
  norm_color = mpl_colors.Normalize(vmin=None, vmax=None, clip=False)
  fig=plt.figure()
  m = Basemap(projection='npstere',boundinglat=65,lon_0=310,resolution='l')
  x,y = m(lon,lat)
  m.scatter(x, y,marker='+',c=data,cmap=cmap, norm=norm_color,edgecolor='none') 
  plt.show()
  </code></pre>
  
  <p>When I just scatter the coordinates: <code>m.scatter(x, y,marker='+')</code> it works fine (I have "+" at the corresponding coordinates, i.e on the 75° latitude projected circle). But when I want to add the data, nothing is displayed.</p>
  
  <p>Where am I not using scatter right ?</p>