text: import sys
  import numpy as np
  from uvw import RectilinearGrid, DataArray
  
  # Creating coordinates
  x = np.linspace(-0.5, 0.5, 10)
  y = np.linspace(-0.5, 0.5, 20)
  
  # A centered disk
  xx, yy = np.meshgrid(x, y, indexing='ij')
  r = np.sqrt(xx**2 + yy**2)
  R = 0.3
  disk = r < R
  
  data = np.zeros([10, 20])
  data[disk] = np.sqrt(1-(r[disk]/R)**2)
  
  cell_data = np.zeros([9, 19])
  cell_data[0::2, 0::2] = 1
  cell_data[1::2, 1::2] = 1
  
  # File object can be used as a context manager
  # and you can write to stdout!
  with RectilinearGrid(sys.stdout, (x, y)) as grid:
    grid.addPointData(DataArray(data, range(2), 'data'))
    grid.addCellData(DataArray(cell_data, range(2), 'chess_board'))
  