def _maybe_add_aer_expectation_instruction(qobj, options):
if 'expectation' in options:
from qiskit.providers.aer.utils.qobj_utils import snapshot_instr, append_instr, get_instr_pos
# add others, how to derive the correct used number of qubits?
# the compiled qobj could be wrong if coupling map is used.
params = options['expectation']['params']
num_qubits = options['expectation']['num_qubits']
for idx in range(len(qobj.experiments)):
# if mulitple params are provided, we assume that each circuit is corresponding one param
# otherwise, params are used for all circuits.
param_idx = idx if len(params) > 1 else 0
snapshot_pos = get_instr_pos(qobj, idx, 'snapshot')
if len(snapshot_pos) == 0: # does not append the instruction yet.
new_ins = snapshot_instr('expectation_value_pauli',
'test',
range(num_qubits),
params=params[param_idx])
qobj = append_instr(qobj, idx, new_ins)
else:
for i in snapshot_pos: # update all expectation_value_snapshot
if qobj.experiments[idx].instructions[
i].type == 'expectation_value_pauli':
qobj.experiments[idx].instructions[i].params = params[
param_idx]
return qobj
def maybe_add_aer_expectation_instruction(qobj, options):
"""
Add aer expectation instruction if `expectation` in the options.
Args:
qobj (QasmQobj): qobj
options (dict): the setting for aer expectation instruction
Returns:
QasmQobj: a mutated qobj with aer expectation instruction inserted
"""
if 'expectation' in options:
from qiskit.providers.aer.utils.qobj_utils \
import snapshot_instr, append_instr, get_instr_pos
# add others, how to derive the correct used number of qubits?
# the compiled qobj could be wrong if coupling map is used.
params = options['expectation']['params']
num_qubits = options['expectation']['num_qubits']
for idx in range(len(qobj.experiments)):
# if multiple params are provided, we assume
# that each circuit is corresponding one param
# otherwise, params are used for all circuits.
param_idx = idx if len(params) > 1 else 0
snapshot_pos = get_instr_pos(qobj, idx, 'snapshot')
if not snapshot_pos: # does not append the instruction yet.
new_ins = snapshot_instr('expectation_value_pauli', 'test',
list(range(num_qubits)), params=params[param_idx])
qobj = append_instr(qobj, idx, new_ins)
else:
for i in snapshot_pos: # update all expectation_value_snapshot
if qobj.experiments[idx].instructions[i].type == 'expectation_value_pauli':
qobj.experiments[idx].instructions[i].params = params[param_idx]
return qobj