from grove.tomography.utils import to_density_matrix, import_qutip
try:
# Python 2
from itertools import izip
except ImportError: # pragma no coverage
# Python 3
izip = zip
import numpy as np
from scipy.sparse import hstack as sphstack, vstack as spvstack
from scipy.sparse.linalg import norm as spnorm
_log = logging.getLogger(__name__)
qt = import_qutip()
FROBENIUS = 'fro'
CHOI = 'choi'
EPS = 1e-8
class CRMBaseError(Exception):
"""
Base class for errors raised when the confusion rate matrix is defective.
"""
pass
class CRMUnnormalizedError(CRMBaseError):
# Python 3
izip = zip
import numpy as np
from pyquil.gates import I, RX, RY, MEASURE
from pyquil.quil import Program
import grove.tomography.utils as ut
import grove.tomography.operator_utils as o_ut
from grove.tomography.operator_utils import QI, QX, QY
from grove.tomography.utils import bitlist_to_int, sample_assignment_probs
_log = logging.getLogger(__name__)
qt = ut.import_qutip()
cvxpy = ut.import_cvxpy()
# We constrain the number of qubits to prevent the use of large amounts of memory, and prohibitively
# long programs.
MAX_QUBITS_STATE_TOMO = 4
MAX_QUBITS_PROCESS_TOMO = MAX_QUBITS_STATE_TOMO // 2
SEED = 137
SOLVER = "SCS"
if qt:
TOMOGRAPHY_GATES = OrderedDict([
(I, QI), (RX(np.pi / 2), (-1j * np.pi / 4 * QX).expm()),
(RY(np.pi / 2), (-1j * np.pi / 4 * QY).expm()),
(RX(np.pi), (-1j * np.pi / 2 * QX).expm())
])
else: # pragma no coverage
