def test_zero(self):
z = Zero()
assert z == 0
assert not (z < 0)
assert z <= 0
assert not (z > 0)
assert z >= 0
assert +z == z
assert -z == z
assert z + 1 == 1
assert z + 3 + z == 3
assert z - 3 == -3
assert z - 3 - z == -3
assert 3 * z == 0
assert z * 3 == 0
assert z / 3 == 0
a = 1
a += z
assert a == 1
a = 1
a += z
assert a == 1
self.assertRaises(ZeroDivisionError, lambda: 3 / z)
assert mkvc(z) == 0
assert sdiag(z) * a == 0
assert z.T == 0
assert z.transpose() == 0
def test_both(self):
z = Zero()
o = Identity()
assert o * z == 0
assert o * z + o == 1
assert o - z == 1
def test_mat_zero(self):
z = Zero()
S = sdiag(np.r_[2, 3])
assert S * z == 0
def sdiag(h):
"""Sparse diagonal matrix"""
if isinstance(h, Zero):
return Zero()
return sp.spdiags(mkvc(h), 0, h.size, h.size, format="csr")