ScheduleBlock

class ScheduleBlock(name=None, metadata=None, alignment_context=None)

Bases: object

A ScheduleBlock is a time-ordered sequence of instructions and transform macro to manage their relative timing. The relative position of the instructions is managed by the alignment_context. This allows ScheduleBlock to support instructions with a parametric duration and allows the lazy scheduling of instructions, i.e. allocating the instruction time just before execution.

ScheduleBlocks should be initialized with one of the following alignment contexts:

AlignLeft: Align instructions in the as-soon-as-possible manner. Instructions are scheduled at the earliest possible time on the channel.
AlignRight: Align instructions in the as-late-as-possible manner. Instructions are scheduled at the latest possible time on the channel.
AlignSequential: Align instructions sequentially even though they are allocated in different channels.
AlignEquispaced: Align instructions with equal interval within a specified duration. Instructions on different channels are aligned sequentially.
AlignFunc: Align instructions with arbitrary position within the given duration. The position is specified by a callback function taking a pulse index j and returning a fractional coordinate in [0, 1].

The ScheduleBlock defaults to the AlignLeft alignment. The timing overlap constraint of instructions is not immediately evaluated, and thus we can assign a parameter object to the instruction duration. Instructions are implicitly scheduled at optimum time when the program is executed.

Note that ScheduleBlock can contain Instruction and other ScheduleBlock to build an experimental program, but Schedule is not supported. This should be added as a Call instruction. This conversion is automatically performed with the pulse builder.

By using ScheduleBlock representation we can fully parametrize pulse waveforms. For example, Rabi schedule generator can be defined as

duration = Parameter('rabi_dur')
amp = Parameter('rabi_amp')
 
block = ScheduleBlock()
rabi_pulse = pulse.Gaussian(duration=duration, amp=amp, sigma=duration/4)
 
block += Play(rabi_pulse, pulse.DriveChannel(0))
block += Call(measure_schedule)

Note that such waveform cannot be appended to the Schedule representation.

In the block representation, the interval between two instructions can be managed with the Delay instruction. Because the schedule block lacks an instruction start time t0, we cannot insert or shift the target instruction. In addition, stored instructions are not interchangable because the schedule block is sensitive to the relative position of instructions. Apart from these differences, the block representation can provide compatible functionality with Schedule representation.

Create an empty schedule block.

Parameters

name (Optional[str]) – Name of this schedule. Defaults to an autogenerated string if not provided.
metadata (Optional[dict]) – Arbitrary key value metadata to associate with the schedule. This gets stored as free-form data in a dict in the metadata attribute. It will not be directly used in the schedule.
alignment_context (AlignmentKind) – AlignmentKind instance that manages scheduling of instructions in this block.

Raises

TypeError – if metadata is not a dict.

Methods

append

ScheduleBlock.append(block, name=None, inplace=True)

Return a new schedule block with block appended to the context block. The execution time is automatically assigned when the block is converted into schedule.

Parameters

block (Union[ScheduleBlock, Instruction]) – ScheduleBlock to be appended.
name (Optional[str]) – Name of the new Schedule. Defaults to name of self.
inplace (bool) – Perform operation inplace on this schedule. Otherwise return a new Schedule.

Return type

ScheduleBlock

Returns

Schedule block with appended schedule.

Raises

PulseError – When invalid schedule type is specified.

assign_parameters

ScheduleBlock.assign_parameters(value_dict, inplace=True)

Assign the parameters in this schedule according to the input.

Parameters

value_dict (Dict[ParameterExpression, Union[ParameterExpression, float]]) – A mapping from Parameters to either numeric values or another Parameter expression.
inplace (bool) – Set True to override this instance with new parameter.

Return type

ScheduleBlock

Returns

Schedule with updated parameters.

ch_duration

ScheduleBlock.ch_duration(*channels)

Return the time of the end of the last instruction over the supplied channels.

Parameters

*channels – Channels within self to include.

Return type

int

draw

ScheduleBlock.draw(style=None, backend=None, time_range=None, time_unit='dt', disable_channels=None, show_snapshot=True, show_framechange=True, show_waveform_info=True, show_barrier=True, plotter='mpl2d', axis=None)

Plot the schedule.

Parameters

style (Optional[Dict[str, Any]]) – Stylesheet options. This can be dictionary or preset stylesheet classes. See IQXStandard, IQXSimple, and IQXDebugging for details of preset stylesheets.
backend (Optional[BaseBackend]) – Backend object to play the input pulse program. If provided, the plotter may use to make the visualization hardware aware.
time_range (Optional[Tuple[int, int]]) – Set horizontal axis limit. Tuple (tmin, tmax).
time_unit (str) – The unit of specified time range either dt or ns. The unit of ns is available only when backend object is provided.
disable_channels (Optional[List[Channel]]) – A control property to show specific pulse channel. Pulse channel instances provided as a list are not shown in the output image.
show_snapshot (bool) – Show snapshot instructions.
show_framechange (bool) – Show frame change instructions. The frame change represents instructions that modulate phase or frequency of pulse channels.
show_waveform_info (bool) – Show additional information about waveforms such as their name.
show_barrier (bool) – Show barrier lines.

plotter (str) –

Name of plotter API to generate an output image. One of following APIs should be specified:

mpl2d: Matplotlib API for 2D image generation.
    Matplotlib API to generate 2D image. Charts are placed along y axis with
    vertical offset. This API takes matplotlib.axes.Axes as ``axis`` input.

axis and style kwargs may depend on the plotter.

axis (Optional[Any]) – Arbitrary object passed to the plotter. If this object is provided, the plotters use a given axis instead of internally initializing a figure object. This object format depends on the plotter. See plotter argument for details.

Returns

Visualization output data. The returned data type depends on the plotter. If matplotlib family is specified, this will be a matplotlib.pyplot.Figure data.

exclude

ScheduleBlock.exclude(*filter_funcs, channels=None, instruction_types=None, time_ranges=None, intervals=None, check_subroutine=True)

Return a Schedule with only the instructions from this Schedule failing at least one of the provided filters. This method is the complement of py:meth:~self.filter, so that:

self.filter(args) | self.exclude(args) == self

Note

This method is currently not supported. Support will be soon added please create an issue if you believe this must be prioritized.

Parameters

filter_funcs (List[Callable]) – A list of Callables which take a (int, Union[‘Schedule’, Instruction]) tuple and return a bool.
channels (Optional[Iterable[Channel]]) – For example, [DriveChannel(0), AcquireChannel(0)].
instruction_types (Union[Iterable[ABCMeta], ABCMeta, None]) – For example, [PulseInstruction, AcquireInstruction].
time_ranges (Optional[Iterable[Tuple[int, int]]]) – For example, [(0, 5), (6, 10)].
intervals (Optional[Iterable[Tuple[int, int]]]) – For example, [(0, 5), (6, 10)].
check_subroutine (bool) – Set True to individually filter instructions inside of a subroutine defined by the Call instruction.

Returns

Schedule consisting of instructions that are not match with filtering condition.

Raises

PulseError – When this method is called. This method will be supported soon.

filter

ScheduleBlock.filter(*filter_funcs, channels=None, instruction_types=None, time_ranges=None, intervals=None, check_subroutine=True)

Return a new Schedule with only the instructions from this ScheduleBlock which pass though the provided filters; i.e. an instruction will be retained iff every function in filter_funcs returns True, the instruction occurs on a channel type contained in channels, the instruction type is contained in instruction_types, and the period over which the instruction operates is fully contained in one specified in time_ranges or intervals.

If no arguments are provided, self is returned.

Note

This method is currently not supported. Support will be soon added please create an issue if you believe this must be prioritized.

Parameters

filter_funcs (List[Callable]) – A list of Callables which take a (int, Union[‘Schedule’, Instruction]) tuple and return a bool.
channels (Optional[Iterable[Channel]]) – For example, [DriveChannel(0), AcquireChannel(0)].
instruction_types (Union[Iterable[ABCMeta], ABCMeta, None]) – For example, [PulseInstruction, AcquireInstruction].
time_ranges (Optional[Iterable[Tuple[int, int]]]) – For example, [(0, 5), (6, 10)].
intervals (Optional[Iterable[Tuple[int, int]]]) – For example, [(0, 5), (6, 10)].
check_subroutine (bool) – Set True to individually filter instructions inside of a subroutine defined by the Call instruction.

Returns

Schedule consisting of instructions that matches with filtering condition.

Raises

PulseError – When this method is called. This method will be supported soon.

get_parameters

ScheduleBlock.get_parameters(parameter_name)

Get parameter object bound to this schedule by string name.

Because different Parameter objects can have the same name, this method returns a list of Parameter s for the provided name.

Parameters

parameter_name (str) – Name of parameter.

Return type

List[Parameter]

Returns

Parameter objects that have corresponding name.

initialize_from

classmethod ScheduleBlock.initialize_from(other_program, name=None)

Create new schedule object with metadata of another schedule object.

Parameters

other_program (Any) – Qiskit program that provides metadata to new object.
name (Optional[str]) – Name of new schedule. Name of block is used by default.

Return type

ScheduleBlock

Returns

New block object with name and metadata.

Raises

PulseError – When other_program does not provide necessary information.

is_parameterized

ScheduleBlock.is_parameterized()

Return True iff the instruction is parameterized.

Return type

bool

is_schedulable

ScheduleBlock.is_schedulable()

Return True if all durations are assigned.

Return type

bool

replace

ScheduleBlock.replace(old, new, inplace=True)

Return a ScheduleBlock with the old component replaced with a new component.

Parameters

old (Union[ScheduleBlock, Instruction]) – Schedule block component to replace.
new (Union[ScheduleBlock, Instruction]) – Schedule block component to replace with.
inplace (bool) – Replace instruction by mutably modifying this ScheduleBlock.

Return type

ScheduleBlock

Returns

The modified schedule block with old replaced by new.

Attributes

alignment_context

Return alignment instance that allocates block component to generate schedule.

blocks

Get the time-ordered instructions from self.

Return type

Tuple[Union[ScheduleBlock, Instruction], ...]

channels

Returns channels that this schedule clock uses.

Return type

Tuple[Channel]

duration

Duration of this schedule block.

Return type

int

instances_counter

Default value: count(0)

instructions

Get the time-ordered instructions from self.

Return type

Tuple[Tuple[int, Instruction]]

metadata

The user provided metadata associated with the schedule.

User provided dict of metadata for the schedule. The metadata contents do not affect the semantics of the program but are used to influence the execution of the schedule. It is expected to be passed between all transforms of the schedule and that providers will associate any schedule metadata with the results it returns from the execution of that schedule.

Return type

Dict[str, Any]

name

Name of this Schedule

Return type

str

parameters

Parameters which determine the schedule behavior.

Return type

Set

prefix

Default value: 'block'

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