# This code is part of Qiskit.
#
# (C) Copyright IBM 2017, 2018.
#
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
#
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.
"""Backend Configuration Classes."""
import re
import copy
import numbers
from typing import Dict, List, Any, Iterable, Tuple, Union
from collections import defaultdict
from qiskit.exceptions import QiskitError
from qiskit.providers.exceptions import BackendConfigurationError
from qiskit.pulse.channels import (
AcquireChannel,
Channel,
ControlChannel,
DriveChannel,
MeasureChannel,
)
from qiskit.utils.deprecation import deprecate_arg
[documentos]class GateConfig:
"""Class representing a Gate Configuration
Attributes:
name: the gate name as it will be referred to in OpenQASM.
parameters: variable names for the gate parameters (if any).
qasm_def: definition of this gate in terms of OpenQASM 2 primitives U
and CX.
"""
def __init__(
self,
name,
parameters,
qasm_def,
coupling_map=None,
latency_map=None,
conditional=None,
description=None,
):
"""Initialize a GateConfig object
Args:
name (str): the gate name as it will be referred to in OpenQASM.
parameters (list): variable names for the gate parameters (if any)
as a list of strings.
qasm_def (str): definition of this gate in terms of OpenQASM 2 primitives U and CX.
coupling_map (list): An optional coupling map for the gate. In
the form of a list of lists of integers representing the qubit
groupings which are coupled by this gate.
latency_map (list): An optional map of latency for the gate. In the
the form of a list of lists of integers of either 0 or 1
representing an array of dimension
len(coupling_map) X n_registers that specifies the register
latency (1: fast, 0: slow) conditional operations on the gate
conditional (bool): Optionally specify whether this gate supports
conditional operations (true/false). If this is not specified,
then the gate inherits the conditional property of the backend.
description (str): Description of the gate operation
"""
self.name = name
self.parameters = parameters
self.qasm_def = qasm_def
# coupling_map with length 0 is invalid
if coupling_map:
self.coupling_map = coupling_map
# latency_map with length 0 is invalid
if latency_map:
self.latency_map = latency_map
if conditional is not None:
self.conditional = conditional
if description is not None:
self.description = description
[documentos] @classmethod
def from_dict(cls, data):
"""Create a new GateConfig object from a dictionary.
Args:
data (dict): A dictionary representing the GateConfig to create.
It will be in the same format as output by
:func:`to_dict`.
Returns:
GateConfig: The GateConfig from the input dictionary.
"""
return cls(**data)
[documentos] def to_dict(self):
"""Return a dictionary format representation of the GateConfig.
Returns:
dict: The dictionary form of the GateConfig.
"""
out_dict = {
"name": self.name,
"parameters": self.parameters,
"qasm_def": self.qasm_def,
}
if hasattr(self, "coupling_map"):
out_dict["coupling_map"] = self.coupling_map
if hasattr(self, "latency_map"):
out_dict["latency_map"] = self.latency_map
if hasattr(self, "conditional"):
out_dict["conditional"] = self.conditional
if hasattr(self, "description"):
out_dict["description"] = self.description
return out_dict
def __eq__(self, other):
if isinstance(other, GateConfig):
if self.to_dict() == other.to_dict():
return True
return False
def __repr__(self):
out_str = f"GateConfig({self.name}, {self.parameters}, {self.qasm_def}"
for i in ["coupling_map", "latency_map", "conditional", "description"]:
if hasattr(self, i):
out_str += ", " + repr(getattr(self, i))
out_str += ")"
return out_str
[documentos]class UchannelLO:
"""Class representing a U Channel LO
Attributes:
q: Qubit that scale corresponds too.
scale: Scale factor for qubit frequency.
"""
def __init__(self, q, scale):
"""Initialize a UchannelLOSchema object
Args:
q (int): Qubit that scale corresponds too. Must be >= 0.
scale (complex): Scale factor for qubit frequency.
Raises:
QiskitError: If q is < 0
"""
if q < 0:
raise QiskitError("q must be >=0")
self.q = q
self.scale = scale
[documentos] @classmethod
def from_dict(cls, data):
"""Create a new UchannelLO object from a dictionary.
Args:
data (dict): A dictionary representing the UChannelLO to
create. It will be in the same format as output by
:func:`to_dict`.
Returns:
UchannelLO: The UchannelLO from the input dictionary.
"""
return cls(**data)
[documentos] def to_dict(self):
"""Return a dictionary format representation of the UChannelLO.
Returns:
dict: The dictionary form of the UChannelLO.
"""
out_dict = {
"q": self.q,
"scale": self.scale,
}
return out_dict
def __eq__(self, other):
if isinstance(other, UchannelLO):
if self.to_dict() == other.to_dict():
return True
return False
def __repr__(self):
return f"UchannelLO({self.q}, {self.scale})"
[documentos]class QasmBackendConfiguration:
"""Class representing an OpenQASM 2.0 Backend Configuration.
Attributes:
backend_name: backend name.
backend_version: backend version in the form X.Y.Z.
n_qubits: number of qubits.
basis_gates: list of basis gates names on the backend.
gates: list of basis gates on the backend.
local: backend is local or remote.
simulator: backend is a simulator.
conditional: backend supports conditional operations.
open_pulse: backend supports open pulse.
memory: backend supports memory.
max_shots: maximum number of shots supported.
"""
_data = {}
def __init__(
self,
backend_name,
backend_version,
n_qubits,
basis_gates,
gates,
local,
simulator,
conditional,
open_pulse,
memory,
max_shots,
coupling_map,
supported_instructions=None,
dynamic_reprate_enabled=False,
rep_delay_range=None,
default_rep_delay=None,
max_experiments=None,
sample_name=None,
n_registers=None,
register_map=None,
configurable=None,
credits_required=None,
online_date=None,
display_name=None,
description=None,
tags=None,
dt=None,
dtm=None,
processor_type=None,
parametric_pulses=None,
**kwargs,
):
"""Initialize a QasmBackendConfiguration Object
Args:
backend_name (str): The backend name
backend_version (str): The backend version in the form X.Y.Z
n_qubits (int): the number of qubits for the backend
basis_gates (list): The list of strings for the basis gates of the
backends
gates (list): The list of GateConfig objects for the basis gates of
the backend
local (bool): True if the backend is local or False if remote
simulator (bool): True if the backend is a simulator
conditional (bool): True if the backend supports conditional
operations
open_pulse (bool): True if the backend supports OpenPulse
memory (bool): True if the backend supports memory
max_shots (int): The maximum number of shots allowed on the backend
coupling_map (list): The coupling map for the device
supported_instructions (List[str]): Instructions supported by the backend.
dynamic_reprate_enabled (bool): whether delay between programs can be set dynamically
(ie via ``rep_delay``). Defaults to False.
rep_delay_range (List[float]): 2d list defining supported range of repetition
delays for backend in μs. First entry is lower end of the range, second entry is
higher end of the range. Optional, but will be specified when
``dynamic_reprate_enabled=True``.
default_rep_delay (float): Value of ``rep_delay`` if not specified by user and
``dynamic_reprate_enabled=True``.
max_experiments (int): The maximum number of experiments per job
sample_name (str): Sample name for the backend
n_registers (int): Number of register slots available for feedback
(if conditional is True)
register_map (list): An array of dimension n_qubits X
n_registers that specifies whether a qubit can store a
measurement in a certain register slot.
configurable (bool): True if the backend is configurable, if the
backend is a simulator
credits_required (bool): True if backend requires credits to run a
job.
online_date (datetime): The date that the device went online
display_name (str): Alternate name field for the backend
description (str): A description for the backend
tags (list): A list of string tags to describe the backend
dt (float): Qubit drive channel timestep in nanoseconds.
dtm (float): Measurement drive channel timestep in nanoseconds.
processor_type (dict): Processor type for this backend. A dictionary of the
form ``{"family": <str>, "revision": <str>, segment: <str>}`` such as
``{"family": "Canary", "revision": "1.0", segment: "A"}``.
- family: Processor family of this backend.
- revision: Revision version of this processor.
- segment: Segment this processor belongs to within a larger chip.
parametric_pulses (list): A list of pulse shapes which are supported on the backend.
For example: ``['gaussian', 'constant']``
**kwargs: optional fields
"""
self._data = {}
self.backend_name = backend_name
self.backend_version = backend_version
self.n_qubits = n_qubits
self.basis_gates = basis_gates
self.gates = gates
self.local = local
self.simulator = simulator
self.conditional = conditional
self.open_pulse = open_pulse
self.memory = memory
self.max_shots = max_shots
self.coupling_map = coupling_map
if supported_instructions:
self.supported_instructions = supported_instructions
self.dynamic_reprate_enabled = dynamic_reprate_enabled
if rep_delay_range:
self.rep_delay_range = [_rd * 1e-6 for _rd in rep_delay_range] # convert to sec
if default_rep_delay is not None:
self.default_rep_delay = default_rep_delay * 1e-6 # convert to sec
# max_experiments must be >=1
if max_experiments:
self.max_experiments = max_experiments
if sample_name is not None:
self.sample_name = sample_name
# n_registers must be >=1
if n_registers:
self.n_registers = 1
# register_map must have at least 1 entry
if register_map:
self.register_map = register_map
if configurable is not None:
self.configurable = configurable
if credits_required is not None:
self.credits_required = credits_required
if online_date is not None:
self.online_date = online_date
if display_name is not None:
self.display_name = display_name
if description is not None:
self.description = description
if tags is not None:
self.tags = tags
# Add pulse properties here because some backends do not
# fit within the Qasm / Pulse backend partitioning in Qiskit
if dt is not None:
self.dt = dt * 1e-9
if dtm is not None:
self.dtm = dtm * 1e-9
if processor_type is not None:
self.processor_type = processor_type
if parametric_pulses is not None:
self.parametric_pulses = parametric_pulses
# convert lo range from GHz to Hz
if "qubit_lo_range" in kwargs:
kwargs["qubit_lo_range"] = [
[min_range * 1e9, max_range * 1e9]
for (min_range, max_range) in kwargs["qubit_lo_range"]
]
if "meas_lo_range" in kwargs:
kwargs["meas_lo_range"] = [
[min_range * 1e9, max_range * 1e9]
for (min_range, max_range) in kwargs["meas_lo_range"]
]
# convert rep_times from μs to sec
if "rep_times" in kwargs:
kwargs["rep_times"] = [_rt * 1e-6 for _rt in kwargs["rep_times"]]
self._data.update(kwargs)
def __getattr__(self, name):
try:
return self._data[name]
except KeyError as ex:
raise AttributeError(f"Attribute {name} is not defined") from ex
[documentos] @classmethod
def from_dict(cls, data):
"""Create a new GateConfig object from a dictionary.
Args:
data (dict): A dictionary representing the GateConfig to create.
It will be in the same format as output by
:func:`to_dict`.
Returns:
GateConfig: The GateConfig from the input dictionary.
"""
in_data = copy.copy(data)
gates = [GateConfig.from_dict(x) for x in in_data.pop("gates")]
in_data["gates"] = gates
return cls(**in_data)
[documentos] def to_dict(self):
"""Return a dictionary format representation of the GateConfig.
Returns:
dict: The dictionary form of the GateConfig.
"""
out_dict = {
"backend_name": self.backend_name,
"backend_version": self.backend_version,
"n_qubits": self.n_qubits,
"basis_gates": self.basis_gates,
"gates": [x.to_dict() for x in self.gates],
"local": self.local,
"simulator": self.simulator,
"conditional": self.conditional,
"open_pulse": self.open_pulse,
"memory": self.memory,
"max_shots": self.max_shots,
"coupling_map": self.coupling_map,
"dynamic_reprate_enabled": self.dynamic_reprate_enabled,
}
if hasattr(self, "supported_instructions"):
out_dict["supported_instructions"] = self.supported_instructions
if hasattr(self, "rep_delay_range"):
out_dict["rep_delay_range"] = [_rd * 1e6 for _rd in self.rep_delay_range]
if hasattr(self, "default_rep_delay"):
out_dict["default_rep_delay"] = self.default_rep_delay * 1e6
for kwarg in [
"max_experiments",
"sample_name",
"n_registers",
"register_map",
"configurable",
"credits_required",
"online_date",
"display_name",
"description",
"tags",
"dt",
"dtm",
"processor_type",
"parametric_pulses",
]:
if hasattr(self, kwarg):
out_dict[kwarg] = getattr(self, kwarg)
out_dict.update(self._data)
if "dt" in out_dict:
out_dict["dt"] *= 1e9
if "dtm" in out_dict:
out_dict["dtm"] *= 1e9
# Use GHz in dict
if "qubit_lo_range" in out_dict:
out_dict["qubit_lo_range"] = [
[min_range * 1e-9, max_range * 1e-9]
for (min_range, max_range) in out_dict["qubit_lo_range"]
]
if "meas_lo_range" in out_dict:
out_dict["meas_lo_range"] = [
[min_range * 1e-9, max_range * 1e-9]
for (min_range, max_range) in out_dict["meas_lo_range"]
]
return out_dict
@property
def num_qubits(self):
"""Returns the number of qubits.
In future, `n_qubits` should be replaced in favor of `num_qubits` for consistent use
throughout Qiskit. Until this is properly refactored, this property serves as intermediate
solution.
"""
return self.n_qubits
def __eq__(self, other):
if isinstance(other, QasmBackendConfiguration):
if self.to_dict() == other.to_dict():
return True
return False
def __contains__(self, item):
return item in self.__dict__
[documentos]class BackendConfiguration(QasmBackendConfiguration):
"""Backwards compat shim representing an abstract backend configuration."""
pass
[documentos]class PulseBackendConfiguration(QasmBackendConfiguration):
"""Static configuration state for an OpenPulse enabled backend. This contains information
about the set up of the device which can be useful for building Pulse programs.
"""
def __init__(
self,
backend_name: str,
backend_version: str,
n_qubits: int,
basis_gates: List[str],
gates: GateConfig,
local: bool,
simulator: bool,
conditional: bool,
open_pulse: bool,
memory: bool,
max_shots: int,
coupling_map,
n_uchannels: int,
u_channel_lo: List[List[UchannelLO]],
meas_levels: List[int],
qubit_lo_range: List[List[float]],
meas_lo_range: List[List[float]],
dt: float,
dtm: float,
rep_times: List[float],
meas_kernels: List[str],
discriminators: List[str],
hamiltonian: Dict[str, Any] = None,
channel_bandwidth=None,
acquisition_latency=None,
conditional_latency=None,
meas_map=None,
max_experiments=None,
sample_name=None,
n_registers=None,
register_map=None,
configurable=None,
credits_required=None,
online_date=None,
display_name=None,
description=None,
tags=None,
channels: Dict[str, Any] = None,
**kwargs,
):
"""
Initialize a backend configuration that contains all the extra configuration that is made
available for OpenPulse backends.
Args:
backend_name: backend name.
backend_version: backend version in the form X.Y.Z.
n_qubits: number of qubits.
basis_gates: list of basis gates names on the backend.
gates: list of basis gates on the backend.
local: backend is local or remote.
simulator: backend is a simulator.
conditional: backend supports conditional operations.
open_pulse: backend supports open pulse.
memory: backend supports memory.
max_shots: maximum number of shots supported.
coupling_map (list): The coupling map for the device
n_uchannels: Number of u-channels.
u_channel_lo: U-channel relationship on device los.
meas_levels: Supported measurement levels.
qubit_lo_range: Qubit lo ranges for each qubit with form (min, max) in GHz.
meas_lo_range: Measurement lo ranges for each qubit with form (min, max) in GHz.
dt: Qubit drive channel timestep in nanoseconds.
dtm: Measurement drive channel timestep in nanoseconds.
rep_times: Supported repetition times (program execution time) for backend in μs.
meas_kernels: Supported measurement kernels.
discriminators: Supported discriminators.
hamiltonian: An optional dictionary with fields characterizing the system hamiltonian.
channel_bandwidth (list): Bandwidth of all channels
(qubit, measurement, and U)
acquisition_latency (list): Array of dimension
n_qubits x n_registers. Latency (in units of dt) to write a
measurement result from qubit n into register slot m.
conditional_latency (list): Array of dimension n_channels
[d->u->m] x n_registers. Latency (in units of dt) to do a
conditional operation on channel n from register slot m
meas_map (list): Grouping of measurement which are multiplexed
max_experiments (int): The maximum number of experiments per job
sample_name (str): Sample name for the backend
n_registers (int): Number of register slots available for feedback
(if conditional is True)
register_map (list): An array of dimension n_qubits X
n_registers that specifies whether a qubit can store a
measurement in a certain register slot.
configurable (bool): True if the backend is configurable, if the
backend is a simulator
credits_required (bool): True if backend requires credits to run a
job.
online_date (datetime): The date that the device went online
display_name (str): Alternate name field for the backend
description (str): A description for the backend
tags (list): A list of string tags to describe the backend
channels: An optional dictionary containing information of each channel -- their
purpose, type, and qubits operated on.
**kwargs: Optional fields.
"""
self.n_uchannels = n_uchannels
self.u_channel_lo = u_channel_lo
self.meas_levels = meas_levels
# convert from GHz to Hz
self.qubit_lo_range = [
[min_range * 1e9, max_range * 1e9] for (min_range, max_range) in qubit_lo_range
]
self.meas_lo_range = [
[min_range * 1e9, max_range * 1e9] for (min_range, max_range) in meas_lo_range
]
self.meas_kernels = meas_kernels
self.discriminators = discriminators
self.hamiltonian = hamiltonian
if hamiltonian is not None:
self.hamiltonian = dict(hamiltonian)
self.hamiltonian["vars"] = {
k: v * 1e9 if isinstance(v, numbers.Number) else v
for k, v in self.hamiltonian["vars"].items()
}
self.rep_times = [_rt * 1e-6 for _rt in rep_times] # convert to sec
self.dt = dt * 1e-9
self.dtm = dtm * 1e-9
if channels is not None:
self.channels = channels
(
self._qubit_channel_map,
self._channel_qubit_map,
self._control_channels,
) = self._parse_channels(channels=channels)
else:
self._control_channels = defaultdict(list)
if channel_bandwidth is not None:
self.channel_bandwidth = [
[min_range * 1e9, max_range * 1e9] for (min_range, max_range) in channel_bandwidth
]
if acquisition_latency is not None:
self.acquisition_latency = acquisition_latency
if conditional_latency is not None:
self.conditional_latency = conditional_latency
if meas_map is not None:
self.meas_map = meas_map
super().__init__(
backend_name=backend_name,
backend_version=backend_version,
n_qubits=n_qubits,
basis_gates=basis_gates,
gates=gates,
local=local,
simulator=simulator,
conditional=conditional,
open_pulse=open_pulse,
memory=memory,
max_shots=max_shots,
coupling_map=coupling_map,
max_experiments=max_experiments,
sample_name=sample_name,
n_registers=n_registers,
register_map=register_map,
configurable=configurable,
credits_required=credits_required,
online_date=online_date,
display_name=display_name,
description=description,
tags=tags,
**kwargs,
)
[documentos] @classmethod
def from_dict(cls, data):
"""Create a new GateConfig object from a dictionary.
Args:
data (dict): A dictionary representing the GateConfig to create.
It will be in the same format as output by :func:`to_dict`.
Returns:
GateConfig: The GateConfig from the input dictionary.
"""
in_data = copy.copy(data)
gates = [GateConfig.from_dict(x) for x in in_data.pop("gates")]
in_data["gates"] = gates
input_uchannels = in_data.pop("u_channel_lo")
u_channels = []
for channel in input_uchannels:
u_channels.append([UchannelLO.from_dict(x) for x in channel])
in_data["u_channel_lo"] = u_channels
return cls(**in_data)
[documentos] def to_dict(self):
"""Return a dictionary format representation of the GateConfig.
Returns:
dict: The dictionary form of the GateConfig.
"""
out_dict = super().to_dict()
u_channel_lo = []
for x in self.u_channel_lo:
channel = []
for y in x:
channel.append(y.to_dict())
u_channel_lo.append(channel)
out_dict.update(
{
"n_uchannels": self.n_uchannels,
"u_channel_lo": u_channel_lo,
"meas_levels": self.meas_levels,
"qubit_lo_range": self.qubit_lo_range,
"meas_lo_range": self.meas_lo_range,
"meas_kernels": self.meas_kernels,
"discriminators": self.discriminators,
"rep_times": self.rep_times,
"dt": self.dt,
"dtm": self.dtm,
}
)
if hasattr(self, "channel_bandwidth"):
out_dict["channel_bandwidth"] = self.channel_bandwidth
if hasattr(self, "meas_map"):
out_dict["meas_map"] = self.meas_map
if hasattr(self, "acquisition_latency"):
out_dict["acquisition_latency"] = self.acquisition_latency
if hasattr(self, "conditional_latency"):
out_dict["conditional_latency"] = self.conditional_latency
if "channels" in out_dict:
out_dict.pop("_qubit_channel_map")
out_dict.pop("_channel_qubit_map")
out_dict.pop("_control_channels")
# Use GHz in dict
if self.qubit_lo_range:
out_dict["qubit_lo_range"] = [
[min_range * 1e-9, max_range * 1e-9]
for (min_range, max_range) in self.qubit_lo_range
]
if self.meas_lo_range:
out_dict["meas_lo_range"] = [
[min_range * 1e-9, max_range * 1e-9]
for (min_range, max_range) in self.meas_lo_range
]
if self.rep_times:
out_dict["rep_times"] = [_rt * 1e6 for _rt in self.rep_times]
out_dict["dt"] *= 1e9
out_dict["dtm"] *= 1e9
if hasattr(self, "channel_bandwidth"):
out_dict["channel_bandwidth"] = [
[min_range * 1e-9, max_range * 1e-9]
for (min_range, max_range) in self.channel_bandwidth
]
if self.hamiltonian:
hamiltonian = copy.deepcopy(self.hamiltonian)
hamiltonian["vars"] = {
k: v * 1e-9 if isinstance(v, numbers.Number) else v
for k, v in hamiltonian["vars"].items()
}
out_dict["hamiltonian"] = hamiltonian
if hasattr(self, "channels"):
out_dict["channels"] = self.channels
return out_dict
def __eq__(self, other):
if isinstance(other, QasmBackendConfiguration):
if self.to_dict() == other.to_dict():
return True
return False
@property
def sample_rate(self) -> float:
"""Sample rate of the signal channels in Hz (1/dt)."""
return 1.0 / self.dt
@property
def control_channels(self) -> Dict[Tuple[int, ...], List]:
"""Return the control channels"""
return self._control_channels
[documentos] def drive(self, qubit: int) -> DriveChannel:
"""
Return the drive channel for the given qubit.
Raises:
BackendConfigurationError: If the qubit is not a part of the system.
Returns:
Qubit drive channel.
"""
if not 0 <= qubit < self.n_qubits:
raise BackendConfigurationError(f"Invalid index for {qubit}-qubit system.")
return DriveChannel(qubit)
[documentos] def measure(self, qubit: int) -> MeasureChannel:
"""
Return the measure stimulus channel for the given qubit.
Raises:
BackendConfigurationError: If the qubit is not a part of the system.
Returns:
Qubit measurement stimulus line.
"""
if not 0 <= qubit < self.n_qubits:
raise BackendConfigurationError(f"Invalid index for {qubit}-qubit system.")
return MeasureChannel(qubit)
[documentos] def acquire(self, qubit: int) -> AcquireChannel:
"""
Return the acquisition channel for the given qubit.
Raises:
BackendConfigurationError: If the qubit is not a part of the system.
Returns:
Qubit measurement acquisition line.
"""
if not 0 <= qubit < self.n_qubits:
raise BackendConfigurationError(f"Invalid index for {qubit}-qubit systems.")
return AcquireChannel(qubit)
[documentos] @deprecate_arg(
"channel",
since="0.19.0",
additional_msg=(
"Instead, use the ``qubits`` argument. This method will now return accurate "
"ControlChannels determined by qubit indices."
),
)
def control(self, qubits: Iterable[int] = None, channel: int = None) -> List[ControlChannel]:
"""
Return the secondary drive channel for the given qubit -- typically utilized for
controlling multiqubit interactions. This channel is derived from other channels.
Args:
qubits: Tuple or list of qubits of the form `(control_qubit, target_qubit)`.
channel: Deprecated.
Raises:
BackendConfigurationError: If the ``qubits`` is not a part of the system or if
the backend does not provide `channels` information in its configuration.
Returns:
List of control channels.
"""
if channel is not None:
qubits = [channel]
try:
if isinstance(qubits, list):
qubits = tuple(qubits)
return self._control_channels[qubits]
except KeyError as ex:
raise BackendConfigurationError(
f"Couldn't find the ControlChannel operating on qubits {qubits} on "
f"{self.n_qubits}-qubit system. The ControlChannel information is retrieved "
"from the backend."
) from ex
except AttributeError as ex:
raise BackendConfigurationError(
f"This backend - '{self.backend_name}' does not provide channel information."
) from ex
[documentos] def get_channel_qubits(self, channel: Channel) -> List[int]:
"""
Return a list of indices for qubits which are operated on directly by the given ``channel``.
Raises:
BackendConfigurationError: If ``channel`` is not a found or if
the backend does not provide `channels` information in its configuration.
Returns:
List of qubits operated on my the given ``channel``.
"""
try:
return self._channel_qubit_map[channel]
except KeyError as ex:
raise BackendConfigurationError(f"Couldn't find the Channel - {channel}") from ex
except AttributeError as ex:
raise BackendConfigurationError(
f"This backend - '{self.backend_name}' does not provide channel information."
) from ex
[documentos] def get_qubit_channels(self, qubit: Union[int, Iterable[int]]) -> List[Channel]:
r"""Return a list of channels which operate on the given ``qubit``.
Raises:
BackendConfigurationError: If ``qubit`` is not a found or if
the backend does not provide `channels` information in its configuration.
Returns:
List of ``Channel``\s operated on my the given ``qubit``.
"""
channels = set()
try:
if isinstance(qubit, int):
for key in self._qubit_channel_map.keys():
if qubit in key:
channels.update(self._qubit_channel_map[key])
if len(channels) == 0:
raise KeyError
elif isinstance(qubit, list):
qubit = tuple(qubit)
channels.update(self._qubit_channel_map[qubit])
elif isinstance(qubit, tuple):
channels.update(self._qubit_channel_map[qubit])
return list(channels)
except KeyError as ex:
raise BackendConfigurationError(f"Couldn't find the qubit - {qubit}") from ex
except AttributeError as ex:
raise BackendConfigurationError(
f"This backend - '{self.backend_name}' does not provide channel information."
) from ex
[documentos] def describe(self, channel: ControlChannel) -> Dict[DriveChannel, complex]:
"""
Return a basic description of the channel dependency. Derived channels are given weights
which describe how their frames are linked to other frames.
For instance, the backend could be configured with this setting::
u_channel_lo = [
[UchannelLO(q=0, scale=1. + 0.j)],
[UchannelLO(q=0, scale=-1. + 0.j), UchannelLO(q=1, scale=1. + 0.j)]
]
Then, this method can be used as follows::
backend.configuration().describe(ControlChannel(1))
>>> {DriveChannel(0): -1, DriveChannel(1): 1}
Args:
channel: The derived channel to describe.
Raises:
BackendConfigurationError: If channel is not a ControlChannel.
Returns:
Control channel derivations.
"""
if not isinstance(channel, ControlChannel):
raise BackendConfigurationError("Can only describe ControlChannels.")
result = {}
for u_chan_lo in self.u_channel_lo[channel.index]:
result[DriveChannel(u_chan_lo.q)] = u_chan_lo.scale
return result
def _parse_channels(self, channels: Dict[set, Any]) -> Dict[Any, Any]:
r"""
Generates a dictionaries of ``Channel``\s, and tuple of qubit(s) they operate on.
Args:
channels: An optional dictionary containing information of each channel -- their
purpose, type, and qubits operated on.
Returns:
qubit_channel_map: Dictionary mapping tuple of qubit(s) to list of ``Channel``\s.
channel_qubit_map: Dictionary mapping ``Channel`` to list of qubit(s).
control_channels: Dictionary mapping tuple of qubit(s), to list of
``ControlChannel``\s.
"""
qubit_channel_map = defaultdict(list)
channel_qubit_map = defaultdict(list)
control_channels = defaultdict(list)
channels_dict = {
DriveChannel.prefix: DriveChannel,
ControlChannel.prefix: ControlChannel,
MeasureChannel.prefix: MeasureChannel,
"acquire": AcquireChannel,
}
for channel, config in channels.items():
channel_prefix, index = self._get_channel_prefix_index(channel)
channel_type = channels_dict[channel_prefix]
qubits = tuple(config["operates"]["qubits"])
if channel_prefix in channels_dict:
qubit_channel_map[qubits].append(channel_type(index))
channel_qubit_map[(channel_type(index))].extend(list(qubits))
if channel_prefix == ControlChannel.prefix:
control_channels[qubits].append(channel_type(index))
return dict(qubit_channel_map), dict(channel_qubit_map), dict(control_channels)
def _get_channel_prefix_index(self, channel: str) -> str:
"""Return channel prefix and index from the given ``channel``.
Args:
channel: Name of channel.
Raises:
BackendConfigurationError: If invalid channel name is found.
Return:
Channel name and index. For example, if ``channel=acquire0``, this method
returns ``acquire`` and ``0``.
"""
channel_prefix = re.match(r"(?P<channel>[a-z]+)(?P<index>[0-9]+)", channel)
try:
return channel_prefix.group("channel"), int(channel_prefix.group("index"))
except AttributeError as ex:
raise BackendConfigurationError(f"Invalid channel name - '{channel}' found.") from ex