Skip to main contentIBM Quantum Documentation
This page is from an old version of Qiskit SDK and does not exist in the latest version. We recommend you migrate to the latest version. See the release notes for more information.

qiskit.ignis.characterization.RabiFitter

class RabiFitter(backend_result, xdata, qubits, fit_p0, fit_bounds=None)

GitHub

Rabi Experiment fitter

See BaseCalibrationFitter __init__

fit_po is [amp, freq, phase, offset]

__init__

__init__(backend_result, xdata, qubits, fit_p0, fit_bounds=None)

See BaseCalibrationFitter __init__

fit_po is [amp, freq, phase, offset]


Methods

__init__(backend_result, xdata, qubits, fit_p0)See BaseCalibrationFitter __init__
add_data(results[, recalc, refit])Add new execution results to previous execution results
fit_data([qid, p0, bounds, series])Fit the curve.
guess_params([qind])Guess fit parameters for rabi oscillation data
pi2_amplitude([qind])Return the pi/2 amplitude from the fit
pi_amplitude([qind])Return the pi amplitude from the fit
plot(qind[, series, ax, show_plot])Plot the data and fit

Attributes

backend_resultReturn the execution results
descriptionReturn the fitter’s purpose, e.g.
fit_funReturn the function used in the fit, e.g.
measured_qubitsReturn the indices of the qubits to be characterized
paramsReturn the fit function parameters that were calculated by curve_fit
params_errReturn the error of the fit function parameters
seriesReturn the list of series for the data
xdataReturn the data points on the x-axis, the independenet parameter which is fit against
ydataReturn the data points on the y-axis

add_data

add_data(results, recalc=True, refit=True)

Add new execution results to previous execution results

Parameters

  • results (Union[Result, List[Result]]) – new execution results
  • recalc (bool) – whether tp recalculate the data
  • refit (bool) – whether to refit the data

backend_result

Return the execution results

Return type

Union[Result, List[Result]]

description

Return the fitter’s purpose, e.g. ‘T1’

Return type

str

fit_data

fit_data(qid=- 1, p0=None, bounds=None, series=None)

Fit the curve.

Compute self._params and self._params_err

Parameters

  • qid (int) – qubit for fitting. If -1 fit for all the qubits
  • p0 (Optional[List[float]]) – initial guess, equivalent to p0 in scipy.optimize
  • bounds (Optional[Tuple[List[float], List[float]]]) – bounds, equivalent to bounds in scipy.optimize
  • series (Optional[str]) – series to fit (if None fit all)

fit_fun

Return the function used in the fit, e.g. BaseFitter._exp_fit_fun

Return type

Callable

guess_params

guess_params(qind=0)

Guess fit parameters for rabi oscillation data

Parameters

qind (int) – qubit index to guess fit parameters for

Returns

List of fit guess parameters

[amp, freq, phase, offset]

Return type

list

measured_qubits

Return the indices of the qubits to be characterized

Return type

List[int]

params

Return the fit function parameters that were calculated by curve_fit

Return type

List[float]

params_err

Return the error of the fit function parameters

Return type

List[float]

pi2_amplitude

pi2_amplitude(qind=- 1)

Return the pi/2 amplitude from the fit

Parameters

qind (int) – qubit index

Returns

π2\frac{\pi}{2} amp

Return type

float

pi_amplitude

pi_amplitude(qind=- 1)

Return the pi amplitude from the fit

Parameters

qind (int) – qubit index

Returns

π\pi amp

Return type

float

plot

plot(qind, series='0', ax=None, show_plot=False)

Plot the data and fit

Parameters

  • qind (int) – qubit index
  • series (str) – data series to plot (for rabi data always ‘0’)
  • ax (Axes) – matploblib axes (if none created)
  • show_plot (bool) – do plot.show

Returns

Plot axes

Return type

Axes

series

Return the list of series for the data

Return type

Optional[List[str]]

xdata

Return the data points on the x-axis, the independenet parameter which is fit against

Return type

Union[List[float], array]

ydata

Return the data points on the y-axis

The data points are returning in the form of a list of dictionaries:

  • ydata[i][‘mean’] is a list, where item

    no. j is the probability of success of qubit i for a circuit that lasts xdata[j].

  • ydata[i][‘std’] is a list, where ydata[‘std’][j] is the

    standard deviation of the success of qubit i.

Return type

List[Dict]

Was this page helpful?
Report a bug or request content on GitHub.