text: import importlib
  import sys
  parameters = importlib.import_module(sys.argv[1])
  globals().update(parameters.__dict__)
  
  def f_bc2(eta):
          for i in xrange(0,4):
                  if BC[i] == 0:
                          if i == 0:
                                  for x in xrange(0,cellsx+2):
                                          eta[x][-1] = eta[x][-3]
                          elif i == 1:
                                  for x in xrange(0,cellsx+2):
                                          eta[x][0] = eta[x][2]
                          elif i == 2:
                                  for y in xrange(0,cellsy+2):
                                          eta[0][y] = eta[2][y]
                          elif i == 3:
                                  for y in xrange(0,cellsy+2):
                                          eta[-1][y] = eta[-3][y]
  	return eta
  