Agent | API Document

    import Agent from 'music-tempo/src/Agent.js'

public class | source

# Agent

Agent is the central class for beat tracking

## Constructor Summary

Public Constructor
public | constructor(tempo: Number, firstBeatTime: Number, firsteventScore: Number, agentList: Array, params: Object) Constructor |

## Member Summary

Public Members
public | agentListRef: Array reference to the agent list |
public | beatInterval: Number the current tempo hypothesis of the Agent, expressed as the beat period |
public | beatTime: Number the time of the most recent beat accepted by this Agent |
public | correctionFactor: Number correction factor for updating beat period |
public | events: Array the array of onsets accepted by this Agent as beats, plus interpolated beats |
public | expiryTime: Number the time after which an Agent that has not accepted any beat will be destroyed |
public | initialBeatInterval: Number the initial tempo hypothesis of the Agent, expressed as the beat period |
public | maxChange: Number the maximum allowed deviation from the initial tempo, expressed as a fraction of the initial beat period |
public | penaltyFactor: Number factor for correcting score, if onset do not coincide precisely with predicted beat time |
public | score: Number sum of salience values of the onsets which have been interpreted as beats by this Agent |
public | toleranceWndInner: Number the maximum time that a beat can deviate from the predicted beat time without a fork occurring |
public | toleranceWndPost: Number the maximum amount by which a beat can be later than the predicted beat time, expressed as a fraction of the beat period |
public | toleranceWndPre: Number the maximum amount by which a beat can be earlier than the predicted beat time, expressed as a fraction of the beat period |
public | totalBeatCount: Number the number of beats found by this Agent, including interpolated beats |

## Method Summary

Public Methods
public | acceptEvent(eventTime: Number, eventScore: Number, err: Number, beatCount: Number) Accept the event time as a beat time, and update the state of the Agent accordingly |
public | clone(): Agent Makes a clone of the Agent |
public | considerEvent(eventTime: Number, eventScore: Number): Boolean The event time is tested if it is a beat time |
public | fillBeats() Interpolates missing beats in the Agent's beat track |

## Public Constructors

### public constructor(tempo: Number, firstBeatTime: Number, firsteventScore: Number, agentList: Array, params: Object) source

Constructor

#### Params:

Name | Type | Attribute | Description
tempo | Number |  | tempo hypothesis of the Agent
firstBeatTime | Number |  | the time of the first beat accepted by this Agent
firsteventScore | Number |  | salience value of the first beat accepted by this Agent
agentList | Array |  | reference to the agent list
params | Object | optional default: {} | parameters
params.expiryTime | Number | optional default: 10 | the time after which an Agent that has not accepted any beat will be destroyed
params.toleranceWndInner | Number | optional default: 0.04 | the maximum time that a beat can deviate from the predicted beat time without a fork occurring
params.toleranceWndPre | Number | optional default: 0.15 | the maximum amount by which a beat can be earlier than the predicted beat time, expressed as a fraction of the beat period
params.toleranceWndPost | Number | optional default: 0.3 | the maximum amount by which a beat can be later than the predicted beat time, expressed as a fraction of the beat period
params.correctionFactor | Number | optional default: 50 | correction factor for updating beat period
params.maxChange | Number | optional default: 0.2 | the maximum allowed deviation from the initial tempo, expressed as a fraction of the initial beat period
params.penaltyFactor | Number | optional default: 0.5 | factor for correcting score, if onset do not coincide precisely with predicted beat time

## Public Members

### public agentListRef: Array source

reference to the agent list

### public beatInterval: Number source

the current tempo hypothesis of the Agent, expressed as the beat period

### public beatTime: Number source

the time of the most recent beat accepted by this Agent

### public correctionFactor: Number source

correction factor for updating beat period

### public events: Array source

the array of onsets accepted by this Agent as beats, plus interpolated beats

### public expiryTime: Number source

the time after which an Agent that has not accepted any beat will be destroyed

### public initialBeatInterval: Number source

the initial tempo hypothesis of the Agent, expressed as the beat period

### public maxChange: Number source

the maximum allowed deviation from the initial tempo, expressed as a fraction of the initial beat period

### public penaltyFactor: Number source

factor for correcting score, if onset do not coincide precisely with predicted beat time

### public score: Number source

sum of salience values of the onsets which have been interpreted as beats by this Agent

### public toleranceWndInner: Number source

the maximum time that a beat can deviate from the predicted beat time without a fork occurring

### public toleranceWndPost: Number source

the maximum amount by which a beat can be later than the predicted beat time, expressed as a fraction of the beat period

### public toleranceWndPre: Number source

the maximum amount by which a beat can be earlier than the predicted beat time, expressed as a fraction of the beat period

### public totalBeatCount: Number source

the number of beats found by this Agent, including interpolated beats

## Public Methods

### public acceptEvent(eventTime: Number, eventScore: Number, err: Number, beatCount: Number) source

Accept the event time as a beat time, and update the state of the Agent accordingly

#### Params:

Name | Type | Attribute | Description
eventTime | Number |  | the event time to be accepted
eventScore | Number |  | salience values of the event time
err | Number |  | the difference between the predicted and actual beat times
beatCount | Number |  | the number of beats since the last beat

### public clone(): Agent source

Makes a clone of the Agent

#### Return:

Agent | agent's clone

### public considerEvent(eventTime: Number, eventScore: Number): Boolean source

The event time is tested if it is a beat time

#### Params:

Name | Type | Attribute | Description
eventTime | Number |  | the event time to be tested
eventScore | Number |  | salience values of the event time

#### Return:

Boolean | indicate whether the given event time was accepted as a beat time

### public fillBeats() source

Interpolates missing beats in the Agent's beat track