ContextualityIndex: Tone Contextuality Index

In m-vidal/pv01: An open source auditory toolbox for perception-based music analysis.

Description

This function calculates the contextuality index. Two methods are used:

• Inspection: compares fixed chord images with running chord images.

• Comparison: compares running chord images with running tone center images.

Usage

ContextualityIndex(inPeriodicityPitch, inSampleFreq, inPeriods,...)

Arguments

inANI	an object of class ANI. It must contain the output of the PeriodicityPitch function: a periodicity pitch image, its sample frequency (in Hz) and the periods of periodicity analysis (in s).
inSnapShot	time where the snapshot should be taken (in s) if negative, the time is taken at abs(inSnapShot) from the end of the sample if empty or not specified, the time of the last sample is used by default
inHalfDecayChords	half decay time for leaky integration into chord image if empty or not specified, 0.1 is used by default.
inHalfDecayToneCenters	half decay time for leaky integration into tone center image if empty or not specified, 1.5 is used by default.
inEnlargement	time by which the input signal is enlarged (in s) if -1, 2*inHalfDecayToneCenters is used if empty or not specified, 0 is used by default.
inPlotFlag	if non-zero, plots are generated if empty or not specified, 0 is used by default

Details

Sample frequency of output signals is the same as inSampleFreq.

Value

An object of class "ANI", which is a list with the following elements:

ChordsImage	local integration of inPeriodicityPitch into chord image.
ToneCentersImage	global integration of inPeriodicityPitch into tone center image
LocalInspection	correspondence between chord taken at snapshot position and running chord image.
GlobalInspection	correspondence between chord taken at snapshot position and running tone center image
Comparison	correspondence between running chord image and running tone center image

Note

Sample frequency of output signals is the same as inSampleFreq.

Author(s)

Marc Vidal (R version). Based on the original code from Marc Leman.

Examples

probe <- ShepardTone(293.66, 1, indBLevel = -20)
s <- c(SchumannKurioseGeschichte, numeric(2205), probe)
ANIs <- CalcANI(s, 22050)
PPs <- PeriodicityPitch(ANIs)
CIs <- ContextualityIndex(PPs)

m-vidal/pv01 documentation built on Dec. 2, 2020, 1:24 a.m.