code: def remove_duplicate_lonlat(lon, lat):
      
  
      a = np.ascontiguousarray(np.vstack((lon, lat)).T)
      unique_a = np.unique(a.view([('', a.dtype)]*a.shape[1]))
      llunique = unique_a.view(a.dtype).reshape((unique_a.shape[0], a.shape[1]))
  
      lon1 = llunique[:,0]
      lat1 = llunique[:,1]
  
      return lon1, lat1
docs: remove duplicates from an array of lon / lat points