def test_set_subcovariance():
a = Parameter("a", 10)
b = Parameter("b", 20)
c = Parameter("c", 30)
pars_0 = Parameters([a, c, b])
pars_0.covariance = np.zeros((3, 3))
pars_1 = Parameters([a, b])
pars_1.covariance = np.array([[2, 3], [6, 7]])
pars_0.set_subcovariance(pars_1)
assert_equal(pars_0.covariance, np.array([[2, 0, 3], [0, 0, 0], [6, 0, 7]]))
def test_get_subcovariance():
a = Parameter("a", 10)
b = Parameter("b", 20)
c = Parameter("c", 30)
pars_0 = Parameters([a, b, c])
pars_0.covariance = np.array([[2, 3, 4], [6, 7, 8], [10, 11, 12]])
pars_1 = Parameters([a, b])
assert_equal(pars_0.get_subcovariance(pars_1), np.array([[2, 3], [6, 7]]))
assert_equal(pars_0.get_subcovariance([c]), np.array([[12]]))