---
title: PHASENumberMetaParameterDefinition
framework: phase
role: symbol
role_heading: Class
path: phase/phasenumbermetaparameterdefinition
---

# PHASENumberMetaParameterDefinition

A specification for a metaparameter defined by a number.

## Declaration

```swift
class PHASENumberMetaParameterDefinition
```

## Overview

Overview Use this class to spawn discrete instances of 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:), then access the instance of this class in the engine’s globalMetaParameters dictionary. Pass it to the PHASEBlendNodeDefinition initializer, init(blendMetaParameterDefinition:identifier:), and then access the instance of this class in a sound event’s metaParameters dictionary. Pass it into the PHASEMappedMetaParameterDefinition initializer, init(inputMetaParameterDefinition:envelope:). Then, access the instance of this class using the mapped parameter’s inputMetaParameterDefinition property.

## Topics

### Creating a Metaparameter Definition

- [init(value:)](phase/phasenumbermetaparameterdefinition/init(value:).md)
- [init(value:identifier:)](phase/phasenumbermetaparameterdefinition/init(value:identifier:).md)
- [init(value:minimum:maximum:)](phase/phasenumbermetaparameterdefinition/init(value:minimum:maximum:).md)
- [init(value:minimum:maximum:identifier:)](phase/phasenumbermetaparameterdefinition/init(value:minimum:maximum:identifier:).md)

### Reistricting the Value

- [minimum](phase/phasenumbermetaparameterdefinition/minimum.md)
- [maximum](phase/phasenumbermetaparameterdefinition/maximum.md)

## Relationships

### Inherits From

- [PHASEMetaParameterDefinition](phase/phasemetaparameterdefinition.md)

### Inherited By

- [PHASEMappedMetaParameterDefinition](phase/phasemappedmetaparameterdefinition.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)

## See Also

### Linear Metaparameters

- [PHASENumberMetaParameter](phase/phasenumbermetaparameter.md)