def test_apply_two_site_gate(backend_dtype_values):
backend = backend_dtype_values[0]
dtype = backend_dtype_values[1]
D, d, N = 10, 2, 10
tensors = [get_random_np((1, d, D), dtype)
] + [get_random_np((D, d, D), dtype)
for _ in range(N - 2)] + [get_random_np((D, d, 1), dtype)]
mps = BaseMPS(tensors, center_position=0, backend=backend)
gate = get_random_np((2, 2, 2, 2), dtype)
tensor1 = mps.tensors[5]
tensor2 = mps.tensors[6]
mps.apply_two_site_gate(gate, 5, 6)
tmp = np.tensordot(tensor1, tensor2, ([2], [0]))
actual = np.transpose(np.tensordot(tmp, gate, ([1, 2], [2, 3])),
(0, 2, 3, 1))
node1 = tn.Node(mps.tensors[5], backend=backend)
node2 = tn.Node(mps.tensors[6], backend=backend)
node1[2] ^ node2[0]
order = [node1[0], node1[1], node2[1], node2[2]]
res = tn.contract_between(node1, node2)
res.reorder_edges(order)
np.testing.assert_allclose(res.tensor, actual)
def test_apply_two_site_wrong_site1_site2_raises_error(backend):
backend = backend_factory.get_backend(backend)
tensor = np.array([[[1., 2., 1.], [1., -2., 1.]],
[[-1., 1., -1.], [-1., 1., -1.]], [[1., 2, 3], [3, 2, 1]]],
dtype=np.float64)
tensors = 6 * [backend.convert_to_tensor(tensor)]
mps = BaseMPS(tensors, backend=backend, center_position=2)
gate = backend.convert_to_tensor(np.ones((2, 2, 2, 2), dtype=np.float64))
with pytest.raises(ValueError):
mps.apply_two_site_gate(gate=gate, site1=2, site2=2)
with pytest.raises(ValueError):
mps.apply_two_site_gate(gate=gate, site1=2, site2=4)
def test_apply_two_site_max_singular_value_not_center_raises_error(backend):
backend = backend_factory.get_backend(backend)
tensor = np.array([[[1., 2., 1.], [1., -2., 1.]],
[[-1., 1., -1.], [-1., 1., -1.]], [[1., 2, 3], [3, 2, 1]]],
dtype=np.float64)
tensors = 6 * [backend.convert_to_tensor(tensor)]
mps = BaseMPS(tensors, backend=backend, center_position=2)
gate = backend.convert_to_tensor(np.ones((2, 2, 2, 2), dtype=np.float64))
with pytest.raises(ValueError):
mps.apply_two_site_gate(gate=gate, site1=3, site2=4, max_singular_values=1)
with pytest.raises(ValueError):
mps.apply_two_site_gate(gate=gate, site1=3, site2=4, max_truncation_err=.1)
def test_apply_two_site_gate_2(backend):
backend = backend_factory.get_backend(backend)
tensor = np.array([[[1., 2., 1.], [1., -2., 1.]],
[[-1., 1., -1.], [-1., 1., -1.]], [[1., 2, 3], [3, 2, 1]]],
dtype=np.float64)
tensors = 6 * [backend.convert_to_tensor(tensor)]
mps = BaseMPS(tensors, backend=backend, center_position=2)
gate = backend.convert_to_tensor(
np.array([[[[0., 1.], [0., 0.]], [[1., 0.], [0., 0.]]],
[[[0., 0.], [0., 1.]], [[0., 0.], [1., 0.]]]],
dtype=np.float64))
actual = mps.apply_two_site_gate(
gate=gate, site1=1, site2=2, max_singular_values=1)
np.testing.assert_allclose(actual[0], 9.133530)
expected = np.array([[5.817886], [9.039142]])
np.testing.assert_allclose(np.abs(mps.tensors[1][0]), expected, rtol=1e-04)
expected = np.array([[0.516264, 0.080136, 0.225841],
[0.225841, 0.59876, 0.516264]])
np.testing.assert_allclose(np.abs(mps.tensors[2][0]), expected, rtol=1e-04)