---
title: TellData (v0.46)
description: API reference for qiskit.algorithms.optimizers.TellData in qiskit v0.46
source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit/0.46/qiskit.algorithms.optimizers.TellData
---

# TellData

*class* `qiskit.algorithms.optimizers.TellData(eval_fun=None, eval_jac=None)`

[GitHub](https://github.com/qiskit/qiskit/tree/stable/0.46/qiskit/algorithms/optimizers/steppable_optimizer.py)

Bases: [`ABC`](https://docs.python.org/3/library/abc.html#abc.ABC)

Base class for argument type of [`tell()`](/docs/api/qiskit/0.46/qiskit.algorithms.optimizers.SteppableOptimizer#tell "qiskit.algorithms.optimizers.SteppableOptimizer.tell").

**Parameters**

- **eval\_fun** ([*float*](https://docs.python.org/3/library/functions.html#float)  *|*[*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[*[*float*](https://docs.python.org/3/library/functions.html#float)*] | None*) – Image of the function at `x_fun`.
- **eval\_jac** (*POINT |* [*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[POINT] | None*) – Image of the gradient-jacobian at `x_jac`.

## Attributes

### eval\_fun

Type: `float | list[float] | None`

Default value: `None`

### eval\_jac

Type: `POINT | list[POINT] | None`

Default value: `None`