FoaXformerMatrix:
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Classes (extension) | Libraries > Ambisonic Toolkit > Matrix & Kernel > FOA

FoaXformerMatrix : FoaMatrix : AtkMatrix : Object
ExtensionExtension

First Order Ambisonic (FOA) transformer matrices
Source: FoaMatrix.sc

Description

Generates transform matrices required by the Ambisonic Toolkit's first order (matrix) transformer, FoaXform.

You may wish to explore the visualizations of the available transforms via FoaXformDisplay.

NOTE: The ATK matrices are required for using some of the matrix transformers. Please see Atk: Installation of ATK dependencies for instructions.

Class Methods

Rotations

FoaXformerMatrix.newRotate(angle: 0)

Rotate around the z-axis.

Arguments:

angle

Rotation angle, in radians.

Discussion:

A rotation of pi/2 will rotate a source at [0, 0] to [pi/2, 0].

NOTE: Corresponding UGen: FoaRotate

FoaXformerMatrix.newTilt(angle: 0)

Rotate around the x-axis.

Arguments:

angle

Rotation angle, in radians.

Discussion:

A rotation of pi/2 will rotate a source at [pi/2, 0] to [0, pi/2].

NOTE: Corresponding UGen: FoaTilt

FoaXformerMatrix.newTumble(angle: 0)

Rotate around the y-axis.

Arguments:

angle

Rotation angle, in radians.

Discussion:

A rotation of pi/2 will rotate a source at [0, 0] to [0, pi/2].

NOTE: Corresponding UGen: FoaTumble

FoaXformerMatrix.newRTT(rotAngle: 0, tilAngle: 0, tumAngle: 0)

Rotate around the z, x and y axes.

Arguments:

rotAngle

Rotation angle around z-axis, in radians.

tilAngle

Rotation angle around x-axis, in radians.

tumAngle

Rotation angle around y-axis, in radians.

Discussion:

Rotate is followed by Tilt and then Tumble.

NOTE: Corresponding UGen: FoaRTT

Reflections

FoaXformerMatrix.newMirrorO

Mirror across the origin.

Discussion:

A source at [pi/4, pi/6] will be mirrored to [-3/4*pi, -pi/6].

FoaXformerMatrix.newMirrorX

Mirror in the x-axis (across the y-z plane).

Discussion:

A source at [pi/4, pi/6] will be mirrored to [3/4*pi, pi/6].

FoaXformerMatrix.newMirrorY

Mirror in the y-axis (across the x-z plane).

Discussion:

A source at [pi/4, pi/6] will be mirrored to [-pi/4, pi/6].

FoaXformerMatrix.newMirrorZ

Mirror in the y-axis (across the x-z plane).

Discussion:

A source at [pi/4, pi/6] will be mirrored to [pi/4, -pi/6].

FoaXformerMatrix.newMirror(theta: 0, phi: 0)

Mirror across an arbitrary plane.

Arguments:

theta

Azimuth for the normal to the plane, in radians.

phi

Elevation for the normal to the plane, in radians.

Discussion:

NOTE: Corresponding UGen: FoaMirror

Directivity

FoaXformerMatrix.newDirectO(angle: 0)

Adjust the soundfield directivity (across the origin).

Arguments:

angle

The distortion angle, in radians. 0 to pi/2

Discussion:

Angle = 0 retains the current directivity of the soundfield. Increasing angle towards pi/2 decreases the directivity, reducing the gains on the directional compenents to zero, and is equivalent to a spatial low-pass filter. The resulting image becomes omnidirectional or directionless.

Imaging is illustrated here.

NOTE: Corresponding UGen: FoaDirectO

FoaXformerMatrix.newDirectX(angle: 0)

Adjust the soundfield directivity along the x-axis.

Arguments:

angle

The distortion angle, in radians. 0 to pi/2

Discussion:

Angle = 0 retains the current directivity of the soundfield. Increasing angle towards pi/2 decreases the directivity along the x-axis, reducing the gain on this axis to zero, and is equivalent to a spatial low-pass filter. The resulting image becomes directionless on the x-axis.

Imaging is illustrated here.

NOTE: Corresponding UGen: FoaDirectX

FoaXformerMatrix.newDirectY(angle: 0)

Adjust the soundfield directivity along the y-axis.

Arguments:

angle

The distortion angle, in radians. 0 to pi/2

Discussion:

Angle = 0 retains the current directivity of the soundfield. Increasing angle towards pi/2 decreases the directivity along the y-axis, reducing the gain on this axis to zero, and is equivalent to a spatial low-pass filter. The resulting image becomes directionless on the y-axis.

Imaging is illustrated here.

NOTE: Corresponding UGen: FoaDirectY

FoaXformerMatrix.newDirectZ(angle: 0)

Adjust the soundfield directivity along the z-axis.

Arguments:

angle

The distortion angle, in radians. 0 to pi/2

Discussion:

Angle = 0 retains the current directivity of the soundfield. Increasing angle towards pi/2 decreases the directivity along the z-axis, reducing the gain on this axis to zero, and is equivalent to a spatial low-pass filter. The resulting image becomes directionless on the z-axis.

NOTE: Corresponding UGen: FoaDirectZ

FoaXformerMatrix.newDirect(angle: 0, theta: 0, phi: 0)

Adjust the soundfield directivity across an arbitrary plane.

Arguments:

angle

The distortion angle, in radians. 0 to pi/2

theta

Azimuth for the normal to the plane, in radians.

phi

Elevation for the normal to the plane, in radians.

Discussion:

Angle = 0 retains the current directivity of the soundfield. Increasing angle towards pi/2 decreases the directivity along the normal defined by theta and phi, reducing the gain on this normal to zero, and is equivalent to a spatial low-pass filter. The resulting image becomes directionless on the normal.

NOTE: Corresponding UGen: FoaDirect

Dominance

FoaXformerMatrix.newDominateX(gain: 0)

Apply dominance along the x-axis.

Arguments:

gain

Dominance gain, in dB.

Discussion:

Positive values of gain increase the gain at [0, 0] to +gain dB, while decreasing the gain at [pi, 0] to -gain. This simultaneously results in a distortion of the image towards [0, 0]. Negative values of gain invert this distortion, distorting towards [pi, 0] . The default, 0, results in no change.

Imaging is illustrated here.

NOTE: Corresponding UGen: FoaDominateX

FoaXformerMatrix.newDominateY(gain: 0)

Apply dominance along the y-axis.

Arguments:

gain

Dominance gain, in dB.

Discussion:

Positive values of gain increase the gain at [pi/2, 0] to +gain dB, while decreasing the gain at [-pi/2, 0] to -gain. This simultaneously results in a distortion of the image towards [pi/2, 0]. Negative values of gain invert this distortion, distorting towards [-pi/2, 0] . The default, 0, results in no change.

NOTE: Corresponding UGen: FoaDominateY

FoaXformerMatrix.newDominateZ(gain: 0)

Apply dominance along the z-axis.

Arguments:

gain

Dominance gain, in dB.

Discussion:

Positive values of gain increase the gain at [0, pi/2] to +gain dB, while decreasing the gain at [0, -pi/2] to -gain. This simultaneously results in a distortion of the image towards [0, pi/2]. Negative values of gain invert this distortion, distorting towards [0, -pi/2] . The default, 0, results in no change.

NOTE: Corresponding UGen: FoaDominateZ

FoaXformerMatrix.newDominate(gain: 0, theta: 0, phi: 0)

Apply dominance along an arbitrary axis.

Arguments:

gain

Dominance gain, in dB.

theta

Azimuth, in radians.

phi

Elevation, in radians.

Discussion:

Applies dominance along the axis defined by theta and phi. See *newDominateX.

NOTE: Corresponding UGen: FoaDominate

Zoom

FoaXformerMatrix.newZoomX(angle: 0)

Apply zoom along the x-axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

Zoom is a normailised dominance variant, specified in terms of a distortion angle. Positive values of angle increase gain at [0, 0], while reducing at [pi, 0]. Negative values do the inverse. The default, 0, results in no change.

Imaging is illustrated here.

NOTE: Corresponding UGen: FoaZoomX

FoaXformerMatrix.newZoomY(angle: 0)

Apply zoom along the y-axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

Zoom is a normailised dominance variant, specified in terms of a distortion angle. Positive values of angle increase gain at [pi/2, 0], while reducing at [-pi/2, 0]. Negative values do the inverse. The default, 0, results in no change.

Imaging is illustrated here.

NOTE: Corresponding UGen: FoaZoomY

FoaXformerMatrix.newZoomZ(angle: 0)

Apply zoom along the z-axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

Zoom is a normailised dominance variant, specified in terms of a distortion angle. Positive values of angle increase gain at [0, pi/2], while reducing at [0, -pi/2]. Negative values do the inverse. The default, 0, results in no change.

NOTE: Corresponding UGen: FoaZoomZ

FoaXformerMatrix.newZoom(angle: 0, theta: 0, phi: 0)

Apply zoom along an arbitrary axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

theta

Azimuth, in radians.

phi

Elevation, in radians.

Discussion:

Applies zoom along the axis defined by theta and phi. See *newZoomX.

NOTE: Corresponding UGen: FoaZoom

Focus

FoaXformerMatrix.newFocusX(angle: 0)

Apply focus along the x-axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

Focus is a normalised dominance variant, specified in terms of a distortion angle. Positive values of angle maintain gain at [0, 0], while reducing at [pi, 0]. Negative values do the inverse. The default, 0, results in no change.

In contrast with zoom, gain is maintained at 0dB in the direction of distortion.

Imaging is illustrated here.

NOTE: Corresponding UGen: FoaFocusX

FoaXformerMatrix.newFocusY(angle: 0)

Apply focus along the y-axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

Focus is a normalised dominance variant, specified in terms of a distortion angle. Positive values of angle maintain gain at [pi/2, 0], while reducing at [-pi/2, 0]. Negative values do the inverse. The default, 0, results in no change.

In contrast with zoom, gain is maintained at 0dB in the direction of distortion.

NOTE: Corresponding UGen: FoaFocusY

FoaXformerMatrix.newFocusZ(angle: 0)

Apply focus along the x-axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

Focus is a normalised dominance variant, specified in terms of a distortion angle. Positive values of angle maintain gain at [0, pi/2], while reducing at [0, -pi/2]. Negative values do the inverse. The default, 0, results in no change.

In contrast with zoom, gain is maintained at 0dB in the direction of distortion.

NOTE: Corresponding UGen: FoaFocusZ

FoaXformerMatrix.newFocus(angle: 0, theta: 0, phi: 0)

Apply focus along an arbitrary axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

theta

Azimuth, in radians.

phi

Elevation, in radians.

Discussion:

Applies focus along the axis defined by theta and phi. See *newFocusX.

NOTE: Corresponding UGen: FoaFocus

Push

FoaXformerMatrix.newPushX(angle: 0)

Apply push along the x-axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

Push is a dominance related transform, specified in terms of a distortion angle. Positive values of angle push the image towards [0, 0]. Negative values push towards [pi, 0]. The default, 0, results in no change.

Imaging is illustrated here.

NOTE: Corresponding UGen: FoaPushX

FoaXformerMatrix.newPushY(angle: 0)

Apply push along the y-axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

Push is a dominance related transform, specified in terms of a distortion angle. Positive values of angle push the image towards [pi/2, 0]. Negative values push towards [-pi/2, 0]. The default, 0, results in no change.

NOTE: Corresponding UGen: FoaPushY

FoaXformerMatrix.newPushZ(angle: 0)

Apply push along the x-axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

Push is a dominance related transform, specified in terms of a distortion angle. Positive values of angle push the image towards [0, pi/2]. Negative values push towards [0, -pi/2]. The default, 0, results in no change.

NOTE: Corresponding UGen: FoaPushZ

FoaXformerMatrix.newPush(angle: 0, theta: 0, phi: 0)

Apply push along an arbitrary axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

theta

Azimuth, in radians.

phi

Elevation, in radians.

Discussion:

Applies push along the axis defined by theta and phi. See *PushX.

NOTE: Corresponding UGen: FoaPush

Press

FoaXformerMatrix.newPressX(angle: 0)

Apply press along the x-axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

Press is a dominance related transform, specified in terms of a distortion angle. Positive values of angle press the image towards [0, 0]. Negative values press towards [pi, 0]. The default, 0, results in no change.

Imaging is illustrated here.

NOTE: Corresponding UGen: FoaPressX

FoaXformerMatrix.newPressY(angle: 0)

Apply press along the x-axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

Press is a dominance related transform, specified in terms of a distortion angle. Positive values of angle press the image towards [pi/2, 0]. Negative values press towards [-pi/2, 0]. The default, 0, results in no change.

NOTE: Corresponding UGen: FoaPressY

FoaXformerMatrix.newPressZ(angle: 0)

Apply press along the z-axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

Press is a dominance related transform, specified in terms of a distortion angle. Positive values of angle press the image towards [0, pi/2]. Negative values press towards [0, -pi/2]. The default, 0, results in no change.

Imaging is illustrated here.

NOTE: Corresponding UGen: FoaPressZ

FoaXformerMatrix.newPress(angle: 0, theta: 0, phi: 0)

Apply press along an arbitrary axis.

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

theta

Azimuth, in radians.

phi

Elevation, in radians.

Discussion:

Applies press along the axis defined by theta and phi. See *PressX.

NOTE: Corresponding UGen: FoaPress

Asymmetry & Balance

FoaXformerMatrix.newAsymmetry(angle: 0)

Apply soundfield asymmetry

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

Positive values of angle rotate [-pi/2, 0] towards [0, 0], and at pi/2 collapse the soundfield to a planewave. Negative values rotate [pi/2, 0] toowards [0, 0]. The default, 0, results in no change.

Imaging is illustrated here.

NOTE: Corresponding UGen: FoaAsymmetry

FoaXformerMatrix.newBalance(angle: 0)

Apply soundfield balance. A synonym for ZoomY

Arguments:

angle

The distortion angle, in radians. -pi/2 to pi/2

Discussion:

See ZoomY.

Imaging is illustrated here.

NOTE: Corresponding UGen: FoaBalance

Matrix & File

FoaXformerMatrix.newFromMatrix(matrix)

Create an instance from a raw 2D Matrix.

Arguments:

matrix

A Matrix in the form of

FoaXformerMatrix.newFromFile(filePathOrName)

Create an FoaXformerMatrix by loading a matrix from a file.

Arguments:

filePathOrName

Can be a path relative to your /extensions/matrices/FOA/xformers folder:

Otherwise a full path to your matrix file.

Discussion:

See the Guide to ATK Matrix Files for more information.

Inherited class methods

Instance Methods

Information

.info

From superclass: AtkMatrix

A convenience method to post the properties of the matrix, including metadata if the matrix was loaded from a .yml file.

.order

From superclass: AtkMatrix

Ambisonic order.

.set

From superclass: FoaMatrix

Describes both the signal set and the tool set, encompassing the Ambisonic order, as well as channel ordering and normalisation.

Ambisonic Toolkit designation indicating Ambisonic order and encoding format. E.g., \FOA, \HOA3.

Answers, \FOA, aka traditional B-format:

Ambisonic OrderComponent OrderingComponent Normalisation
1stFurse-Malham (FuMa)Gerzon / Furse-Malham (MaxN)

.type

From superclass: FoaMatrix

Returns:

'xformer'

.op

From superclass: AtkMatrix

Answers 'matrix', i.e. the type of operation used to compute the resulting signals.

.kind

From superclass: AtkMatrix

Answers the kind of transformer.

Discussion:

.dim

From superclass: FoaMatrix

Answers the number of transformer dimensions: 3D.

.numChannels

From superclass: FoaMatrix

Answers the number of channels.

Discussion:

All Transformer matricies are square: 4.

.dirChannels

.dirChannels = value

A convenience method providing polymorphism with FoaEncoderMatrix: -dirChannels and FoaDecoderMatrix: -dirChannels.

Returns:

[ inf, inf, inf , inf ]

.directions

From superclass: FoaMatrix

A synonym for -dirChannels

.numInputs

From superclass: AtkMatrix

A convenience method providing polymorphism with FoaEncoderMatrix: -numInputs and FoaDecoderMatrix: -numInputs.

.dirInputs

From superclass: FoaMatrix

A convenience method providing polymorphism with FoaEncoderMatrix: -dirInputs and FoaDecoderMatrix: -dirInputs.

.numOutputs

From superclass: AtkMatrix

A convenience method providing polymorphism with FoaEncoderMatrix: -numOutputs and FoaDecoderMatrix: -numOutputs.

.dirOutputs

From superclass: FoaMatrix

A convenience method providing polymorphism with FoaEncoderMatrix: -dirOutputs and FoaDecoderMatrix: -dirOutputs.

Matrix

.matrix

From superclass: AtkMatrix

Returns the raw coefficient Matrix.

.asArray

From superclass: AtkMatrix

Returns the matrix as a new Array of rows.

File handling

.fileName

From superclass: AtkMatrix

Answers the name of the file used to create the instance, or nil if not created by loading a matrix from a file.

.filePath

From superclass: AtkMatrix

Answers the path of the file used to create the instance, or nil if not created by loading a matrix from a file.

.fileParse

From superclass: AtkMatrix

If the instance was created by loading a .yml file, this method returns the IdentityDictionary containing the parsed metadata. This can be useful if anything was stored in the metadata that can be subsequently used once reloaded, such as encoding directions, rotations, etc.

NOTE: For simply a quick glance at the metadata, it's recommended to use -info.

.writeToFile(fileNameOrPath, note, attributeDictionary, overwrite: false)

From superclass: AtkMatrix

Write the matrix to a file

Arguments:

fileNameOrPath

A String of the file name. The file extension determines the format:

  • .yml allows for additional user-specified metadata (recommended).
  • .txt writes the matrix coefficients only, in rows.
  • .mosl.txt creates basic matrix files compatible with the ATK for Reaper, a set of JSFX plugins for the Reaper DAW.

You may provide a full path if you would like to save the file somewhere other than the default location in the Atk extensions folder. See the Discussion below for more information.

note

A String that is a short description or bit of info about the matrix to store for future reference.

attributeDictionary

A Dictionary containing any information that's useful to store in key:value pairs. Keys that match getters in the AtkMatrix will take precedence over the defaults. See the Discussion for more details.

overwrite

A boolean specifying whether you'd like to force overwriting an existing file of the same name and extension.

Discussion:

The Guide to ATK Matrix Files offers examples and more discussion regarding writing and reading matrices and metadata, including how to generate matrices for use in Reaper.

Inherited instance methods

Examples

Transforming FOA

helpfile source: /Library/Application Support/SuperCollider/downloaded-quarks/atk-sc3/HelpSource/Classes/FoaXformerMatrix.schelp
link::Classes/FoaXformerMatrix::