'Create LogQuantity subclass objects for some physical units,
and basic check on transformations'

@pytest.mark.parametrize(u'lq_cls,    physical_unit', itertools.product(lq_subclasses, pu_sample))
def test_subclass_creation(self, lq_cls, physical_unit):

    value = np.arange(1.0, 10.0)
    log_q = lq_cls((value * physical_unit))
    assert (log_q.unit.physical_unit == physical_unit)
    assert (log_q.unit.function_unit == log_q.unit._default_function_unit)
    assert_allclose(log_q.physical.value, value)
    with pytest.raises(ValueError):
        lq_cls(value, physical_unit)
