def target(self, qubits, channel):
"""Changes the target qubit of a 'Local' channel.
Args:
qubits (hashable, iterable): The new target for this channel. Must
correspond to a qubit ID in device or an iterable of qubit IDs,
when multi-qubit adressing is possible.
channel (str): The channel's name provided when declared. Must be
a channel with 'Local' addressing.
"""
if channel not in self._channels:
raise ValueError("Use the name of a declared channel.")
if isinstance(qubits, Iterable) and not isinstance(qubits, str):
qs = set(qubits)
else:
qs = {qubits}
if not qs.issubset(self._qids):
raise ValueError("The given qubits have to belong to the device.")
if self._channels[channel].addressing != 'Local':
raise ValueError("Can only choose target of 'Local' channels.")
elif len(qs) > self._channels[channel].max_targets:
raise ValueError(
"This channel can target at most "
f"{self._channels[channel].max_targets} qubits at a time"
)
basis = self._channels[channel].basis
phase_refs = {self._phase_ref[basis][q].last_phase for q in qs}
if len(phase_refs) != 1:
raise ValueError("Cannot target multiple qubits with different "
"phase references for the same basis.")
try:
last = self._last(channel)
if last.targets == qs:
warnings.warn("The provided qubits are already the target. "
"Skipping this target instruction.")
return
ti = last.tf
retarget = self._channels[channel].retarget_time
elapsed = ti - self._last_target[channel]
delta = np.clip(retarget - elapsed, 0, retarget)
if delta != 0:
with warnings.catch_warnings():
warnings.simplefilter("ignore")
delta = validate_duration(np.clip(delta, 16, np.inf))
tf = ti + delta
except ValueError:
ti = -1
tf = 0
self._last_target[channel] = tf
self._add_to_schedule(channel, _TimeSlot('target', ti, tf, qs))
def __init__(self, duration):
"""Initializes a waveform with a given duration.
Args:
duration (int): The waveforms duration (in multiples of 4 ns).
"""
self._duration = validate_duration(duration,
min_duration=16,
max_duration=4194304)
def _delay(self, duration, channel):
self._validate_channel(channel)
if self.is_parametrized():
return
last = self._last(channel)
ti = last.tf
tf = ti + validate_duration(duration)
self._add_to_schedule(channel, _TimeSlot('delay', ti, tf,
last.targets))
def delay(self, duration, channel):
"""Idles a given channel for a specific duration.
Args:
duration (int): Time to delay (in multiples of 4 ns).
channel (str): The channel's name provided when declared.
"""
last = self._last(channel)
ti = last.tf
tf = ti + validate_duration(duration)
self._add_to_schedule(channel,
_TimeSlot('delay', ti, tf, last.targets))
def _target(self, qubits, channel):
self._validate_channel(channel)
try:
qs = set(qubits) if not isinstance(qubits, str) else {qubits}
except TypeError:
qs = {qubits}
if self._channels[channel].addressing != 'Local':
raise ValueError("Can only choose target of 'Local' channels.")
elif len(qs) > self._channels[channel].max_targets:
raise ValueError(
"This channel can target at most "
f"{self._channels[channel].max_targets} qubits at a time")
if self.is_parametrized():
for q in qs:
if q not in self._qids and not isinstance(q, Parametrized):
raise ValueError("All non-variable qubits must belong to "
"the register.")
return
elif not qs.issubset(self._qids):
raise ValueError("All given qubits must belong to the register.")
basis = self._channels[channel].basis
phase_refs = {self._phase_ref[basis][q].last_phase for q in qs}
if len(phase_refs) != 1:
raise ValueError("Cannot target multiple qubits with different "
"phase references for the same basis.")
try:
last = self._last(channel)
if last.targets == qs:
warnings.warn("The provided qubits are already the target. "
"Skipping this target instruction.")
return
ti = last.tf
retarget = self._channels[channel].retarget_time
elapsed = ti - self._last_target[channel]
delta = np.clip(retarget - elapsed, 0, retarget)
if delta != 0:
with warnings.catch_warnings():
warnings.simplefilter("ignore")
delta = validate_duration(np.clip(delta, 16, np.inf))
tf = ti + delta
except ValueError:
ti = -1
tf = 0
self._last_target[channel] = tf
self._add_to_schedule(channel, _TimeSlot('target', ti, tf, qs))