FormatChannels: Format Channel Names

In patrickreidy/ag501: Carstens AG501 Electromagnetic Articulograph

Description

Expand a character vector whose elements denote sensor names into a character vector whose elements denote names for the channels of data that were recorded for those sensors.

Usage

FormatChannels(sensors = character(), n = 16)

Arguments

sensors	A character vector, names for sensors that were attached to the participant and connected to sockets in the Carstens Sensin box. The position of a name in this vector is interpreted as the number of the socket to which the sensor was connected. Default is character().
n	An atomic numeric, the number of sensors/sockets for which the Carstens Sweepsaver software recorded data. (This number is recorded in the NumberOfChannels field in the header of a .pos file.) Default is 16.

Details

For each sensor, seven channels of data are recorded:

• x: position of the sensor along the antero-posterior axis (i.e., orthogonal to the coronal plane)

• y: position of the sensor along the lateral axis (i.e., orthogonal to the sagittal plane)

• z: position of the sensor along the vertical axis (i.e., orthogonal to the transverse plane)

• phi: rotation angle between the x-axis and the projection of the sensor axis onto the transverse plane (i.e., the azimuthal angle)

• theta: rotation angle between the z-axis and the sensor axis (i.e., the polar angle)

• rms: the root-mean-squared error between the measured amplitudes from the articulograph's transmitter coils and the expected amplitudes given the positional and rotational coordinates of the sensor

• extra: an empty channel that serves as a placeholder for future development

The x, y, and z axes define a three-dimensional right-handed Cartesian coordinate system. The phi and theta angles define the sensor axis in a spherical coordinate system.

Because seven channels of data are recorded for each sensor, the returned character vector has 7n elements.

Note that the MATLAB toolbox SMASH names the positional axes differently: the antero-posterior axis is named z; the lateral axis, x; and the vertical axis, y.

Value

A character vector, the result of first formatting sensors (by calling FormatSensors) and then suffixing each formatted sensor name with x, y, z, phi, theta, rms, and extra.

See Also

FormatSensors

Examples

FormatChannels(n = 8)
FormatChannels(sensors = c("HL", "HR", "TB", "TD", "TT"), n = 16)
FormatChannels(sensors = c("", "", "TB", "TD", "TT"), n = 16)

patrickreidy/ag501 documentation built on May 30, 2019, 10:01 p.m.