def test_specify_sites(self, cyclic):
sites = [12, 13, 15, 16, 17]
k = MPS_rand_state(5, 7, cyclic=cyclic, sites=sites, nsites=20)
assert set(k.tags) == {f'I{i}' for i in sites}
def test_known_bad_case(self, cyclic):
k = MPS_rand_state(5, 10, cyclic=cyclic)
rhoc_ab = k.partial_trace_compress(sysa=range(2), sysb=range(2, 4))
inds = ['kA', 'kB'], ['bA', 'bB']
x = rhoc_ab.trace(*inds)
assert_allclose(1.0, x, rtol=1e-3)
def test_compress_site(self):
psi = MPS_rand_state(10, 7)
psi.compress_site(3, max_bond=1)
assert psi.bond_sizes() == [2, 4, 1, 1, 7, 7, 7, 4, 2]
assert psi.calc_current_orthog_center() == (3, 3)
psi = MPS_rand_state(10, 7)
psi.compress_site(0, max_bond=1)
assert psi.bond_sizes() == [1, 7, 7, 7, 7, 7, 7, 4, 2]
assert psi.calc_current_orthog_center() == (0, 0)
psi = MPS_rand_state(10, 7)
psi.compress_site(9, max_bond=1)
assert psi.bond_sizes() == [2, 4, 7, 7, 7, 7, 7, 7, 1]
assert psi.calc_current_orthog_center() == (9, 9)
def test_subtract(self):
a, b, c = (MPS_rand_state(10, 7) for _ in 'abc')
ab = a.H @ b
ac = a.H @ c
abmc = a.H @ (b - c)
assert_allclose(ab - ac, abmc)
def test_can_change_data(self):
p = MPS_rand_state(3, 10)
assert_allclose(p.H @ p, 1)
p[1].modify(data=np.random.randn(10, 10, 2))
assert abs(p.H @ p - 1) > 1e-13
def test_compress_form(self):
p = MPS_rand_state(20, 20)
p.compress('left')
assert p.count_canonized() == (19, 0)
p.compress('right')
assert p.count_canonized() == (0, 19)
p.compress(7)
assert p.count_canonized() == (7, 12)
p = MPS_rand_state(20, 20)
p.compress('flat', absorb='left')
assert p.count_canonized() == (0, 0)
def test_swap_gating(self):
psi0 = MPS_rand_state(20, 5)
CNOT = qu.controlled('not')
psi0XX = psi0.gate(CNOT, (4, 13))
psi0XX_s = psi0.gate_with_auto_swap(CNOT, (4, 13))
assert psi0XX.H @ psi0XX_s == pytest.approx(1.0)
def test_sites_mpo_mps_product(self, cyclic):
k = MPS_rand_state(13, 7, cyclic=cyclic)
X = MPO_rand_herm(3, 5, sites=[3, 6, 7], nsites=13, cyclic=cyclic)
b = k.H
k.align_(X, b)
assert (k & X & b) ^ ...
def test_gate_split(self):
psi = MPS_rand_state(10, 3)
psi2 = psi.copy()
G = qu.eye(2) & qu.eye(2)
psi.gate_split_(G, (2, 3), cutoff=0)
assert psi.bond_size(2, 3) == 6
assert psi.H @ psi2 == pytest.approx(1.0)
# check a unitary application
G = qu.rand_uni(2**2)
psi.gate_split_(G, (7, 8))
psi.compress()
assert psi.bond_size(2, 3) == 3
assert psi.bond_size(7, 8) > 3
assert psi.H @ psi == pytest.approx(1.0)
assert abs(psi2.H @ psi) < 1.0
# check matches dense application of gate
psid = psi2.to_dense()
Gd = qu.ikron(G, [2] * 10, (7, 8))
assert psi.to_dense().H @ (Gd @ psid) == pytest.approx(1.0)
def test_canonize_cyclic(self, dtype, block):
k = MPS_rand_state(40, 10, dtype=dtype, cyclic=True)
b = k.H
k.add_tag('KET')
b.add_tag('BRA')
kb = (b | k)
assert not np.allclose(k[block].H @ k[block], 1.0)
assert not np.allclose(b[block].H @ b[block], 1.0)
k.canonize_cyclic(block, bra=b)
assert_allclose(k[block].H @ k[block], 1.0, rtol=2e-4)
assert_allclose(b[block].H @ b[block], 1.0, rtol=2e-4)
ii = kb.select(block, which='!any') ^ all
if isinstance(block, slice):
start, stop = block.start, block.stop
else:
start, stop = block, block + 1
assert len(kb.select_tensors(block, 'any')) == 2 * (stop - start)
ul, = bonds(kb[k.site_tag(start - 1), 'BRA'], kb[k.site_tag(start),
'BRA'])
ur, = bonds(kb[k.site_tag(stop - 1), 'BRA'], kb[k.site_tag(stop),
'BRA'])
ll, = bonds(kb[k.site_tag(start - 1), 'KET'], kb[k.site_tag(start),
'KET'])
lr, = bonds(kb[k.site_tag(stop - 1), 'KET'], kb[k.site_tag(stop),
'KET'])
ii = ii.to_dense((ul, ur), (ll, lr))
assert_allclose(ii, np.eye(ii.shape[0]), rtol=0.001, atol=0.001)
def test_construct_tridiag_works(self, sysa, sysb):
p = MPS_rand_state(12, 7)
pX = PTPTLazyMPS(p, sysa=sysa, sysb=sysb)
for _ in construct_lanczos_tridiag_PTPTLazyMPS(pX, 5):
pass
def test_graph(self):
import matplotlib
matplotlib.use('Template')
k = MPS_rand_state(10, 7, normalize=False)
k.graph(color=['I0', 'I2'])
def test_cut_iter(self):
psi = MPS_rand_state(10, 7, cyclic=True)
pp = psi.H & psi
bnds = bonds(pp[0], pp[-1])
assert sum(tn ^ all for tn in pp.cut_iter(*bnds)) == pytest.approx(1.0)
assert pp ^ all == pytest.approx(1.0)
