def test_pde_critical_input():
"""test some wrong input and edge cases"""
# test whether reserved symbols can be used as variables
grid = grids.UnitGrid([4])
eq = PDE({"E": 1})
res = eq.solve(ScalarField(grid), t_range=2)
np.testing.assert_allclose(res.data, 2)
with pytest.raises(ValueError):
PDE({"t": 1})
eq = PDE({"u": 1})
assert eq.expressions == {"u": "1.0"}
with pytest.raises(ValueError):
eq.evolution_rate(FieldCollection.scalar_random_uniform(2, grid))
eq = PDE({"u": 1, "v": 2})
assert eq.expressions == {"u": "1.0", "v": "2.0"}
with pytest.raises(ValueError):
eq.evolution_rate(ScalarField.random_uniform(grid))
eq = PDE({"u": "a"})
with pytest.raises(RuntimeError):
eq.evolution_rate(ScalarField.random_uniform(grid))
eq = PDE({"x": "x"})
with pytest.raises(ValueError):
eq.evolution_rate(ScalarField(grid))
def test_pde_wrong_input():
"""test some wrong input"""
with pytest.raises(ValueError):
PDE({"t": 1})
with pytest.raises(ValueError):
PDE({"E": 1})
with pytest.raises(ValueError):
PDE({"E": 1, "t": 0})
grid = grids.UnitGrid([4])
eq = PDE({"u": 1})
assert eq.expressions == {"u": "1.0"}
with pytest.raises(ValueError):
eq.evolution_rate(FieldCollection.scalar_random_uniform(2, grid))
eq = PDE({"u": 1, "v": 2})
assert eq.expressions == {"u": "1.0", "v": "2.0"}
with pytest.raises(ValueError):
eq.evolution_rate(ScalarField.random_uniform(grid))
eq = PDE({"u": "a"})
with pytest.raises(RuntimeError):
eq.evolution_rate(ScalarField.random_uniform(grid))
eq = PDE({"x": "x"})
with pytest.raises(ValueError):
eq.evolution_rate(ScalarField(grid))
def test_pde_2scalar():
"""test PDE with two scalar fields"""
eq = PDE({"u": "laplace(u) - u", "v": "- u * v"})
assert not eq.explicit_time_dependence
assert not eq.complex_valued
grid = grids.UnitGrid([8])
field = FieldCollection.scalar_random_uniform(2, grid)
res_a = eq.solve(field, t_range=1, dt=0.01, backend="numpy", tracker=None)
res_b = eq.solve(field, t_range=1, dt=0.01, backend="numba", tracker=None)
res_a.assert_field_compatible(res_b)
np.testing.assert_allclose(res_a.data, res_b.data)