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

# qiskit\_noise\_learning.math.EnumeratedIndexedSpace

*class* `qiskit_noise_learning.math.EnumeratedIndexedSpace(indices: frozenset[Index])`

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

Bases: [`IndexedSpace`](/docs/api/qiskit-noise-learning/generated/math-indexed-space "qiskit_noise_learning.math.indexed_space.IndexedSpace")\[`Index`]

An indexed space backed by an explicit finite collection of indices.

**Parameters**

**indices** – The collection of valid indices in this space.

### \_\_init\_\_

`__init__(indices: frozenset[Index])`

## Methods

|                                                                                                                                                 |   |
| ----------------------------------------------------------------------------------------------------------------------------------------------- | - |
| [`__init__`](#qiskit_noise_learning.math.EnumeratedIndexedSpace.__init__ "qiskit_noise_learning.math.EnumeratedIndexedSpace.__init__")(indices) |   |

## Attributes

|                                                                                                                         |                                           |
| ----------------------------------------------------------------------------------------------------------------------- | ----------------------------------------- |
| [`dim`](#qiskit_noise_learning.math.EnumeratedIndexedSpace.dim "qiskit_noise_learning.math.EnumeratedIndexedSpace.dim") | The dimension (cardinality) of the space. |

### dim

Type: [`int`](https://docs.python.org/3/library/functions.html#int)

The dimension (cardinality) of the space.

May be `math.inf` for infinite-dimensional spaces.