def test_init_array(self):
"""Test initialization from array."""
rho = self.rand_rho(3)
state = DensityMatrix(rho)
self.assertAllClose(state.data, rho)
self.assertEqual(state.dim, 3)
self.assertEqual(state.dims(), (3,))
rho = self.rand_rho(2 * 3 * 4)
state = DensityMatrix(rho, dims=[2, 3, 4])
self.assertAllClose(state.data, rho)
self.assertEqual(state.dim, 2 * 3 * 4)
self.assertEqual(state.dims(), (2, 3, 4))
def test_init_array_qubit(self):
"""Test subsystem initialization from N-qubit array."""
# Test automatic inference of qubit subsystems
rho = self.rand_rho(8)
for dims in [None, 8]:
state = DensityMatrix(rho, dims=dims)
self.assertAllClose(state.data, rho)
self.assertEqual(state.dim, 8)
self.assertEqual(state.dims(), (2, 2, 2))
def test_tensor(self):
"""Test tensor method."""
for _ in range(10):
rho0 = self.rand_rho(2)
rho1 = self.rand_rho(3)
target = np.kron(rho0, rho1)
state = DensityMatrix(rho0).tensor(DensityMatrix(rho1))
self.assertEqual(state.dim, 6)
self.assertEqual(state.dims(), (3, 2))
self.assertAllClose(state.data, target)
def test_expand(self):
"""Test expand method."""
for _ in range(10):
rho0 = self.rand_rho(2)
rho1 = self.rand_rho(3)
target = np.kron(rho1, rho0)
state = DensityMatrix(rho0).expand(DensityMatrix(rho1))
self.assertEqual(state.dim, 6)
self.assertEqual(state.dims(), (2, 3))
self.assertAllClose(state.data, target)
