def test_planar_y_decoder_partial_recovery(code, syndrome_index,
expected_syndrome_indices):
partial_recovery = PlanarYDecoder._partial_recovery(code, syndrome_index)
print()
print(code.new_pauli(partial_recovery))
syndrome = pt.bsp(partial_recovery, code.stabilizers.T)
syndrome_indices = code.syndrome_to_plaquette_indices(syndrome)
assert syndrome_indices == expected_syndrome_indices, 'syndrome_indices not as expected'
def test_planar_y_decoder_partial_recovery_idempotence():
# tests for bug where destabilizer modified cached return value of _snake_fill
code = PlanarCode(4, 3)
syndrome_index = (2, 1)
# create partial_recovery1, destabilzer and partial_recovery2, copying to test for changes
partial_recovery1 = np.copy(
PlanarYDecoder._partial_recovery(code, syndrome_index))
destabilizer = np.copy(PlanarYDecoder._destabilizer(code, syndrome_index))
partial_recovery2 = np.copy(
PlanarYDecoder._partial_recovery(code, syndrome_index))
print(code.new_pauli(partial_recovery1))
print(code.new_pauli(destabilizer))
print(code.new_pauli(partial_recovery2))
assert np.array_equal(
partial_recovery1,
partial_recovery2), '_partial_recovery is not idempotent'
assert not np.array_equal(
partial_recovery2, destabilizer), '_partial_recovery == _destabilizer'
def test_planar_y_decoder_residual_recovery(code, syndrome_index):
partial_recovery = PlanarYDecoder._partial_recovery(code, syndrome_index)
syndrome = pt.bsp(partial_recovery, code.stabilizers.T)
residual_recovery = PlanarYDecoder._residual_recovery(code, syndrome)
assert not np.any(partial_recovery ^ residual_recovery
), 'Residual recovery does not match partial recovery'