---
title: IndexedVector (latest version)
description: API reference for qiskit_noise_learning.math.IndexedVector in the latest version of qiskit-noise-learning
source: https://quantum.cloud.ibm.com/docs/en/api/qiskit-noise-learning/generated/math-indexed-vector
---

# qiskit\_noise\_learning.math.IndexedVector

*class* `qiskit_noise_learning.math.IndexedVector`

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

Bases: [`dict`](https://docs.python.org/3/library/stdtypes.html#dict)\[`Index`, [`float`](https://docs.python.org/3/library/functions.html#float)]

A vector of floats with arbitrary index, or axis label, data.

### \_\_init\_\_

`__init__(*args, **kwargs)`

## Methods

|                                                                                                                                          |                                                                                                                                                                                                                                      |
| ---------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| [`__init__`](#qiskit_noise_learning.math.IndexedVector.__init__ "qiskit_noise_learning.math.IndexedVector.__init__")(\*args, \*\*kwargs) |                                                                                                                                                                                                                                      |
| [`add`](#qiskit_noise_learning.math.IndexedVector.add "qiskit_noise_learning.math.IndexedVector.add")(other)                             | Return a new indexed vector that is the sum of self and other.                                                                                                                                                                       |
| `clear`()                                                                                                                                |                                                                                                                                                                                                                                      |
| `copy`()                                                                                                                                 |                                                                                                                                                                                                                                      |
| `fromkeys`(iterable\[, value])                                                                                                           | Create a new dictionary with keys from iterable and values set to value.                                                                                                                                                             |
| `get`(key\[, default])                                                                                                                   | Return the value for key if key is in the dictionary, else default.                                                                                                                                                                  |
| `items`()                                                                                                                                |                                                                                                                                                                                                                                      |
| `keys`()                                                                                                                                 |                                                                                                                                                                                                                                      |
| [`mul`](#qiskit_noise_learning.math.IndexedVector.mul "qiskit_noise_learning.math.IndexedVector.mul")(const)                             | Return a new indexed vector by multipling self with a constant.                                                                                                                                                                      |
| `pop`(k\[,d])                                                                                                                            | If the key is not found, return the default if given; otherwise, raise a KeyError.                                                                                                                                                   |
| `popitem`()                                                                                                                              | Remove and return a (key, value) pair as a 2-tuple.                                                                                                                                                                                  |
| `setdefault`(key\[, default])                                                                                                            | Insert key with a value of default if key is not in the dictionary.                                                                                                                                                                  |
| `update`(\[E, ]\*\*F)                                                                                                                    | If E is present and has a .keys() method, then does: for k in E.keys(): D\[k] = E\[k] If E is present and lacks a .keys() method, then does: for k, v in E: D\[k] = v In either case, this is followed by: for k in F: D\[k] = F\[k] |
| `values`()                                                                                                                               |                                                                                                                                                                                                                                      |

### add

`add(other: Self) → Self`

Return a new indexed vector that is the sum of self and other.

### mul

`mul(const: float) → Self`

Return a new indexed vector by multipling self with a constant.