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

# qiskit\_noise\_learning.analysis.LSQLinearSolve

*class* `qiskit_noise_learning.analysis.LSQLinearSolve(**lsq_linear_opts)`

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

Bases: `ModelSolve`

Solves for the [`ModelData`](/docs/api/qiskit-noise-learning/generated/data-model-data "qiskit_noise_learning.data.ModelData") using SciPy’s linear least squares solver.

See SciPy’s [documentation](https://docs.scipy.org/doc/scipy/reference/generated/scipy.optimize.lsq_linear.html) for details on the method. See `ModelSolve` for more details about the general responsibility of a model solver in this library.

**Parameters**

**\*\*lsq\_linear\_opts** – The options passed on to the SciPy solver.

### \_\_init\_\_

`__init__(**lsq_linear_opts)`

## Methods

|                                                                                                                                                       |                                                                                                                                                                       |
| ----------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [`__init__`](#qiskit_noise_learning.analysis.LSQLinearSolve.__init__ "qiskit_noise_learning.analysis.LSQLinearSolve.__init__")(\*\*lsq\_linear\_opts) |                                                                                                                                                                       |
| `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`  | The data level this stage reads.  |
| `output_level` | The data level this stage writes. |