Constant
class Constant(duration, amp, name=None, limit_amplitude=None)
Bases: qiskit.pulse.library.symbolic_pulses.SymbolicPulse
A simple constant pulse, with an amplitude value and a duration:
Create new pulse instance.
Parameters
- duration (
Union
[int
,ParameterExpression
]) – Pulse length in terms of the sampling period dt. - amp (
Union
[complex
,ParameterExpression
]) – The amplitude of the constant square pulse. - name (
Optional
[str
]) – Display name for this pulse envelope. - limit_amplitude (
Optional
[bool
]) – IfTrue
, then limit the amplitude of the waveform to 1. The default isTrue
and the amplitude is constrained to 1.
Methods
draw
Constant.draw(style=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. SeeIQXStandard
,IQXSimple
, andIQXDebugging
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 eitherdt
orns
. The unit ofns
is available only whenbackend
object is provided. -
show_waveform_info (
bool
) – Show waveform annotations, i.e. name, of waveforms. SetTrue
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 givenaxis
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.
get_waveform
Constant.get_waveform()
Return a Waveform with samples filled according to the formula that the pulse represents and the parameter values it contains.
Since the returned array is a discretized time series of the continuous function, this method uses a midpoint sampler. For duration
, return:
Return type
Returns
A waveform representation of this pulse.
Raises
- PulseError – When parameters are not assigned.
- PulseError – When expression for pulse envelope is not assigned.
is_parameterized
Constant.is_parameterized()
Return True iff the instruction is parameterized.
Return type
bool
validate_parameters
Constant.validate_parameters()
Validate parameters.
Raises
PulseError – If the parameters passed are not valid.
Return type
None
Attributes
constraints
Return symbolic expression for the pulse parameter constraints.
Return type
Expr
duration
envelope
Return symbolic expression for the pulse envelope.
Return type
Expr
id
Unique identifier for this pulse.
Return type
int
limit_amplitude
Default value: True
name
parameters
Return type
Dict
[str
, Any
]
pulse_type
Return display name of the pulse shape.
Return type
str
valid_amp_conditions
Return symbolic expression for the pulse amplitude constraints.
Return type
Expr