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# PHASENumberMetaParameterDefinition

A specification for a metaparameter defined by a number.

```
class PHASENumberMetaParameterDefinition
```

## Overview

Use this class to spawn discrete instances of [`PHASENumberMetaParameter`](/documentation/PHASE/PHASENumberMetaParameter), for example, a “player speed” metaparameter that the app changes gradually from `0.0` to `1.0`.

To use a number metaparameter, create an instance of this class and:

- Register it with the engine by calling [`registerGlobalMetaParameter(metaParameterDefinition:)`](/documentation/PHASE/PHASEAssetRegistry/registerGlobalMetaParameter(metaParameterDefinition:)), then access the instance of this class in the engine’s [`globalMetaParameters`](/documentation/PHASE/PHASEAssetRegistry/globalMetaParameters) dictionary.
- Pass it to the [`PHASEBlendNodeDefinition`](/documentation/PHASE/PHASEBlendNodeDefinition) initializer, [`init(blendMetaParameterDefinition:identifier:)`](/documentation/PHASE/PHASEBlendNodeDefinition/init(blendMetaParameterDefinition:identifier:)), and then access the instance of this class in a sound event’s [`metaParameters`](/documentation/PHASE/PHASESoundEvent/metaParameters) dictionary.
- Pass it into the [`PHASEMappedMetaParameterDefinition`](/documentation/PHASE/PHASEMappedMetaParameterDefinition) initializer, [`init(inputMetaParameterDefinition:envelope:)`](/documentation/PHASE/PHASEMappedMetaParameterDefinition/init(inputMetaParameterDefinition:envelope:)). Then, access the instance of this class using the mapped parameter’s [`inputMetaParameterDefinition`](/documentation/PHASE/PHASEMappedMetaParameterDefinition/inputMetaParameterDefinition) property.

## Topics

### Creating a Metaparameter Definition

[`-  initWithValue:`](/documentation/PHASE/PHASENumberMetaParameterDefinition/init(value:))

Creates a specification for a metaparameter with the given numeric value.

[`-  initWithValue:identifier:`](/documentation/PHASE/PHASENumberMetaParameterDefinition/init(value:identifier:))

Creates a specification for a named metaparameter with the given numeric value.

[`-  initWithValue:minimum:maximum:`](/documentation/PHASE/PHASENumberMetaParameterDefinition/init(value:minimum:maximum:))

Creates a specification for a metaparameter with the given numeric value and range.

[`-  initWithValue:minimum:maximum:identifier:`](/documentation/PHASE/PHASENumberMetaParameterDefinition/init(value:minimum:maximum:identifier:))

Creates a specification for a named metaparameter with the given numeric value and range.

### Reistricting the Value

[`minimum`](/documentation/PHASE/PHASENumberMetaParameterDefinition/minimum)

The lowest possible number for the value.

[`maximum`](/documentation/PHASE/PHASENumberMetaParameterDefinition/maximum)

The highest possible number for the value.

## Relationships

### Conforms To

[`Hashable`](/documentation/Swift/Hashable)

[`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible)

[`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible)

[`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol)

[`Equatable`](/documentation/Swift/Equatable)

[`CVarArg`](/documentation/Swift/CVarArg)

### Inherited By

[`PHASEMappedMetaParameterDefinition`](/documentation/PHASE/PHASEMappedMetaParameterDefinition)

### Inherits From

[`PHASEMetaParameterDefinition`](/documentation/PHASE/PHASEMetaParameterDefinition)

---

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