---
title: ComputeObservables (latest version)
description: API reference for qiskit_noise_learning.analysis.ComputeObservables in the latest version of qiskit-noise-learning
source: https://quantum.cloud.ibm.com/docs/en/api/qiskit-noise-learning/generated/analysis-compute-observables
---

# qiskit\_noise\_learning.analysis.ComputeObservables

*class* `qiskit_noise_learning.analysis.ComputeObservables`

[GitHub](https://github.com/Qiskit/qiskit-noise-learning/tree/stable/0.1/qiskit_noise_learning/analysis/compute_observables.py)

Bases: [`AnalysisStage`](/docs/api/qiskit-noise-learning/generated/analysis-analysis-stage "qiskit_noise_learning.analysis.analysis_pipeline.AnalysisStage")

Compute observable data from raw data.

This analysis stage utilizes existing relations between paths and instruction sequences in the [`Fit`](/docs/api/qiskit-noise-learning/generated/analysis-fit "qiskit_noise_learning.analysis.Fit") to determine how to compute observables. If relations are not specified, they are greedily constructed by exhaustively comparing paths in `fit.paths` and the instruction sequences in `fit.raw_data`. Note that in this latter case, `fit.paths` is not updated and will therefore remain `None`.

### \_\_init\_\_

`__init__()`

## Methods

|                                                                                                                                          |                                                                                                                                                                       |
| ---------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [`__init__`](#qiskit_noise_learning.analysis.ComputeObservables.__init__ "qiskit_noise_learning.analysis.ComputeObservables.__init__")() |                                                                                                                                                                       |
| `run`(fit)                                                                                                                               | Run this stage, returning a new [`Fit`](/docs/api/qiskit-noise-learning/generated/analysis-fit "qiskit_noise_learning.analysis.Fit") with the output level populated. |

## Attributes

|                                                                                                                                                    |                                   |
| -------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------- |
| [`input_level`](#qiskit_noise_learning.analysis.ComputeObservables.input_level "qiskit_noise_learning.analysis.ComputeObservables.input_level")    | The data level this stage reads.  |
| [`output_level`](#qiskit_noise_learning.analysis.ComputeObservables.output_level "qiskit_noise_learning.analysis.ComputeObservables.output_level") | The data level this stage writes. |

### input\_level

The data level this stage reads.

### output\_level

The data level this stage writes.