# T1Fitter¶

class T1Fitter(backend_result, xdata, qubits, fit_p0, fit_bounds, time_unit='micro-seconds')[ソース]

Estimate T1, based on experiments outcomes,

The experiments were created by t1_circuits, and executed on the device.

The probabilities of measuring 1 is assumed to be of the form

$f(t) = A\mathrm{e}^{-t/T_1}+B,$

for unknown parameters A, B, and T1.

パラメータ
• backend_result (Result) – result of execution of t1_circuits on the backend.

• xdata (Union[List[float], array]) – delay times of the T1 circuits.

• qubits (List[int]) – indices of the qubits whose T1『s are to be measured.

• fit_p0 (List[float]) – initial values to the fit parameters, where the order is $$(A, T_1, B)$$.

• fit_bounds (Tuple[List[float], List[float]]) – bounds on the parameters to fit. The first tuple is the lower bounds, in the order $$(A, T_1, B)$$. The second tuple is the upper bounds.

• time_unit (str) – unit of delay times in xdata.

Methods

 add_data Add new execution results to previous execution results fit_data Fit the curve. plot Plot coherence data. time Return the characteristic time for the given qubit and series time_err Return the error of characteristic time for the given qubit and series

Attributes

backend_result

Return the execution results

Union[Result, List[Result]]

description

Return the fitter’s purpose, e.g. 『T1』

str

fit_fun

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

Callable

measured_qubits

Return the indices of the qubits to be characterized

List[int]

params

Return the fit function parameters that were calculated by curve_fit

List[float]

params_err

Return the error of the fit function parameters

List[float]

series

Return the list of series for the data

Optional[List[str]]

xdata

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

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.

List[Dict]