def test1():
q = Quantity(1, 'km')
assert_eq(q.SI, Quantity(1000, 'm'))
q = Quantity(1, 'm')
assert_eq(q, q.tounit('m'))
q2 = q.copy()
q.inunit('m')
assert_eq(q, q2)
def test3():
q = Quantity(1, 'km')
q.inunit('m')
assert_quantity(q, 1000, 'm')
def test_derived_units2():
a = Quantity(4., 'Jy/detector', {'detector': Quantity(2,'arcsec^2')})
a.inunit(a.unit + ' / arcsec^2 * detector')
assert_quantity(a, 2, 'Jy / arcsec^2')
def test_conversion_error():
a = Quantity(1., 'kloug')
assert_raises(UnitError, lambda: a.inunit('notakloug'))
assert_raises(UnitError, lambda: a.inunit('kloug^2'))
