# CompleteMeasFitter

`qiskit.utils.mitigation.CompleteMeasFitter(results, state_labels, qubit_list=None, circlabel='')`

Bases: `object`

(opens in a new tab)

Deprecated: Measurement correction fitter for a full calibration

Initialize a measurement calibration matrix from the results of running the circuits returned by measurement_calibration_circuits

A wrapper for the tensored fitter

This class is not a public API. The internals are not stable and will likely change. It is used solely for the `measurement_error_mitigation_cls`

kwarg of the `QuantumInstance`

class’s constructor (as a class not an instance). Anything outside of that usage does not have the normal user-facing API stability.

The class `qiskit.utils.mitigation.fitters.CompleteMeasFitter`

is deprecated as of qiskit-terra 0.24.0. It will be removed no earlier than 3 months after the release date. For code migration guidelines, visit https://qisk.it/qi_migration (opens in a new tab).

**Parameters**

**results**– the results of running the measurement calibration circuits. If this is None the user will set a calibration matrix later.**state_labels**(*List*(opens in a new tab)*[**str*(opens in a new tab)*]*) – list of calibration state labels returned from measurement_calibration_circuits. The output matrix will obey this ordering.**qubit_list**(*List*(opens in a new tab)*[**int*(opens in a new tab)*]*) – List of the qubits (for reference and if the subset is needed). If None, the qubit_list will be created according to the length of state_labels[0].**circlabel**(*str*(opens in a new tab)) – if the qubits were labeled.

## Attributes

### cal_matrix

Return cal_matrix.

### filter

Return a measurement filter using the cal matrix.

### qubit_list

Return list of qubits.

### state_labels

Return state_labels.

## Methods

### add_data

`add_data(new_results, rebuild_cal_matrix=True)`

Add measurement calibration data

**Parameters**

**new_results**(*list*(opens in a new tab)*or**qiskit.result.Result*) – a single result or list of result objects.**rebuild_cal_matrix**(*bool*(opens in a new tab)) – rebuild the calibration matrix

### readout_fidelity

`readout_fidelity(label_list=None)`

Based on the results, output the readout fidelity which is the normalized trace of the calibration matrix

**Parameters**

**label_list** (*bool* (opens in a new tab)) – If None, returns the average assignment fidelity of a single state. Otherwise it returns the assignment fidelity to be in any one of these states averaged over the second index.

**Returns**

readout fidelity (assignment fidelity)

**Return type**

numpy.array

**Additional Information:**

The on-diagonal elements of the calibration matrix are the probabilities of measuring state ‘x’ given preparation of state ‘x’ and so the normalized trace is the average assignment fidelity

### subset_fitter

`subset_fitter(qubit_sublist)`

Return a fitter object that is a subset of the qubits in the original list.

**Parameters**

**qubit_sublist** (*list* (opens in a new tab)) – must be a subset of qubit_list

**Returns**

**A new fitter that has the calibration for a**

subset of qubits

**Return type**

**Raises**

**QiskitError** – If the calibration matrix is not initialized