def test_add_remove_interaction_simple():
mesh = CuboidMesh(nx=10, ny=10, nz=10, unit_length=1e-9)
name = 'test_add_remove_intn_simple'
sim = Sim(mesh, name=name)
sim.set_m(lambda pos: (0, 0, 1))
sim.set_Ms(5.8e5)
exch = UniformExchange(A=1e-11, name='Exchange')
zee = Zeeman((0, 0, 0.05 / constant.mu_0), name='Zeeman')
sim.add(exch)
sim.add(zee)
sim.driver.run_until(1e-9)
sim.remove('Zeeman')
sim.driver.run_until(2e-9)
f = open(name + '.txt')
lines = f.read().split('\n')
headers = lines[0].split()
first_data = lines[2].split()
last_data = lines[2].split()
# Find the position in the data table
position = headers.index('E_Zeeman')
assert np.abs(float(last_data[position])) < 1e-15