WaveNumber:
Filter:
Classes (extension) | Libraries > Ambisonic Toolkit > Coefficients & Theory

WaveNumber : Object
ExtensionExtension

Higher Order Ambisonic (HOA) radial utilities

Description

Higher Order Ambisonic (HOA) radial utilities. Useful for finding ambisonic decoder effective radius, effective order and effective frequency.

Class Methods

WaveNumber.new(waveNumber)

Create a new instance, in terms of spatial frequency.

Arguments:

waveNumber

Angular wavenumber, in radians per meter.

WaveNumber.newFreq(freq, speedOfSound)

Create a new instance, in terms of frequency by the relationship:

2pi * freq / speedOfSound.

Arguments:

freq

Frequency, in Hz.

speedOfSound

Speed of sound, in meters per second. Def: AtkHoa.speedOfSound

WaveNumber.newWn(wn, sampleRate, speedOfSound)

Create a new instance, in terms of normalized frequency wn by the relationship:

pi * wn * sampleRate / speedOfSound.

Arguments:

wn

Normalized frequency. DC = 0.0, Nyquist = 1.0;

sampleRate

Sample rate, in Hz.

speedOfSound

Speed of sound, in meters per second. Def: AtkHoa.speedOfSound

WaveNumber.newRadius(radius, order)

Create a new instance, in terms of distance and effective order by the relationship:

order / radius.

Arguments:

radius

Radius, in meters. Def: AtkHoa.refRadius

order

Ambisonic order. Def: AtkHoa.defaultOrder

WaveNumber.newDelay(delay, order, speedOfSound)

Create a new instance, in terms of time and effective order by the relationship:

order / (delay * speedOfSound).

Arguments:

delay

Radial delay, in seconds.

order

Ambisonic order. Def: AtkHoa.defaultOrder

speedOfSound

Speed of sound, in meters per second. Def: AtkHoa.speedOfSound

Inherited class methods

Instance Methods

Radius & delay

.radius(order)

Return effective radius, in meters.

Arguments:

order

Ambisonic order. Def: AtkHoa.defaultOrder

.delay(order, speedOfSound)

Return effective delay, in seconds.

Arguments:

order

Ambisonic order. Def: AtkHoa.defaultOrder

speedOfSound

Speed of sound, in meters per second. Def: AtkHoa.speedOfSound

Effective order

.orderAtRadius(radius)

Return effective ambisonic order, given radius.

Arguments:

radius

Radius, in meters. Def: AtkHoa.refRadius

.orderAtDelay(delay, speedOfSound)

Return effective ambisonic order, given delay.

Arguments:

delay

Delay, in seconds.

speedOfSound

Speed of sound, in meters per second. Def: AtkHoa.speedOfSound

Frequency

.freq(speedOfSound)

Return frequency, in Hz.

Arguments:

speedOfSound

Speed of sound, in meters per second. Def: AtkHoa.speedOfSound

.wn(sampleRate, speedOfSound)

Return normalized frequency. DC = 0.0, Nyquist = 1.0.

Arguments:

sampleRate

Sample rate, in Hz.

speedOfSound

Speed of sound, in meters per second. Def: AtkHoa.speedOfSound

.waveNumber

Angular wavenumber, in radians per meter.

NFE

.proxWeights(radius, order)

Return complex near-field effect proximity radial filtering coefficients, collected by Associated Legendre degree (ℓ).

Arguments:

radius

Radius, in meters. Def: AtkHoa.refRadius

order

Ambisonic order. Def: AtkHoa.defaultOrder

Discussion:

These complex weights represent the magnitude and phase change of each degree when encoding an otherwise far-field source at a distance of radius.

See further discussion on The Near-Field Effect (NFE).

.distWeights(radius, order)

Return complex near-field effect distance radial filtering coefficients, collected by Associated Legendre degree (ℓ).

Arguments:

radius

Radius, in meters. Def: AtkHoa.refRadius

order

Ambisonic order. Def: AtkHoa.defaultOrder

Discussion:

These complex weights are the reciprocal of -proxWeights.

See further discussion on The Near-Field Effect (NFE).

.ctrlWeights(encRadius, decRadius, order)

Return complex near-field effect control radial filtering coefficients, collected by Associated Legendre degree (ℓ).

Arguments:

encRadius

Encoding radius, in meters. Def: AtkHoa.refRadius

decRadius

Decoding radius, in meters. Def: AtkHoa.refRadius

order

Ambisonic order. Def: AtkHoa.defaultOrder

Discussion:

These complex weights represent a ratio of the -proxWeights of the encoding radius to the decoding radius, i.e. proxWeights(encRadius) / proxWeights(decRadius).

See further discussion on The Near-Field Effect (NFE).

Inherited instance methods

Examples

Effective radius

Effective order

Effective frequency