qiskit.pulse.Constant

class Constant(duration, amp, name=None)

A simple constant pulse, with an amplitude value and a duration:

\[f(x) = amp , 0 <= x < duration f(x) = 0 , elsewhere\]

Initialize the constant-valued pulse.

Parameters

• duration (Union[int, ParameterExpression]) – Pulse length in terms of the the sampling period dt.

• amp (Union[complex, ParameterExpression]) – The amplitude of the constant square pulse.

• name (Optional[str]) – Display name for this pulse envelope.

__init__(duration, amp, name=None)

Initialize the constant-valued pulse.

Parameters

• duration (Union[int, ParameterExpression]) – Pulse length in terms of the the sampling period dt.

• amp (Union[complex, ParameterExpression]) – The amplitude of the constant square pulse.

• name (Optional[str]) – Display name for this pulse envelope.

Methods

__init__(duration, amp[, name])	Initialize the constant-valued pulse.
assign(parameter, value)	Assign one parameter to a value, which can either be numeric or another parameter expression.
assign_parameters(value_dict)	Return a new ParametricPulse with parameters assigned.
draw([dt, style, filename, interp_method, …])	Plot the interpolated envelope of pulse.
get_waveform()	Return a Waveform with samples filled according to the formula that the pulse represents and the parameter values it contains.
is_parameterized()	Return True iff the instruction is parameterized.
validate_parameters()	Validate parameters.

Attributes

amp	The constant value amplitude.
id	Unique identifier for this pulse.
parameters	Return a dictionary containing the pulse’s parameters.

property amp

The constant value amplitude.

Return type

Union[complex, ParameterExpression]

assign(parameter, value)

Assign one parameter to a value, which can either be numeric or another parameter expression.

Return type

ParametricPulse

assign_parameters(value_dict)

Return a new ParametricPulse with parameters assigned.

Parameters

value_dict (Dict[ParameterExpression, Union[ParameterExpression, float, int]]) – A mapping from Parameters to either numeric values or another Parameter expression.

Return type

ParametricPulse

Returns

New pulse with updated parameters.

draw(dt=None, style=None, filename=None, interp_method=None, scale=None, interactive=None, draw_title=None, backend=None, time_range=None, time_unit='dt', show_waveform_info=True, plotter='mpl2d', axis=None)

Plot the interpolated envelope of pulse.

Parameters

• style (Optional[Dict[str, Any]]) – Stylesheet options. This can be dictionary or preset stylesheet classes. See :py:class:~`qiskit.visualization.pulse_v2.stylesheets.IQXStandard`, :py:class:~`qiskit.visualization.pulse_v2.stylesheets.IQXSimple`, and :py:class:~`qiskit.visualization.pulse_v2.stylesheets.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.

• show_waveform_info (bool) – Show waveform annotations, i.e. name, of waveforms. Set True to show additional information about waveforms.

• 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.

• dt (Optional[Any]) – Deprecated. This argument is used by the legacy pulse drawer.

• filename (Optional[Any]) – Deprecated. This argument is used by the legacy pulse drawer. To save output image, you can call .savefig method with returned Matplotlib Figure object.

• interp_method (Optional[Any]) – Deprecated. This argument is used by the legacy pulse drawer.

• scale (Optional[Any]) – Deprecated. This argument is used by the legacy pulse drawer.

• interactive (Optional[Any]) – Deprecated. This argument is used by the legacy pulse drawer.

• draw_title (Optional[Any]) – Deprecated. This argument is used by the legacy pulse drawer.

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.

get_waveform()

Return a Waveform with samples filled according to the formula that the pulse represents and the parameter values it contains.

Return type

Waveform

property id

Unique identifier for this pulse.

Return type

int

is_parameterized()

Return True iff the instruction is parameterized.

Return type

bool

property parameters

Return a dictionary containing the pulse’s parameters.

Return type

Dict[str, Any]

validate_parameters()

Validate parameters.

Raises

PulseError – If the parameters passed are not valid.

Return type

None