seewave (version 2.2.4)

diffcumspec: Difference between two cumulative frequency spectra

Description

This function compares two distributions (e.g. two frequency spectra) by computing the difference between two cumulative frequency spectra

Usage

diffcumspec(spec1, spec2, f = NULL, mel = FALSE, 
plot = FALSE, type = "l", lty = c(1, 2), col = c(2, 4, 8),
flab = NULL, alab = "Cumulated amplitude",
flim = NULL, alim = NULL,
title = TRUE, legend = TRUE, ...)

Value

A numeric vector of length 1 returning the difference between the two spectra. No unit.

Details

Both spectra are transformed into cumulative distribution functions (CDF).
Spectral difference is then computed according to:
$$D_{cf}(x, y) = \frac{\sum_{i=1}^{n}|X_{i} - Y_{i}|}{n}, with with X and Y the spectrum CDFs, and D \in [0,1].$$

References

Lellouch L, Pavoine S, Jiguet F, Glotin H, Sueur J (2014) Monitoring temporal change of bird communities with dissimilarity acoustic indices. Methods in Ecology and Evolution, in press.

See Also

kl.dist, ks.dist, simspec, diffspec, logspec.dist, itakura.dist

Examples

## Hz scale
data(tico)
data(orni)
orni.hz <- meanspec(orni, plot=FALSE)
tico.hz <- meanspec(tico, plot=FALSE)
diffcumspec(orni.hz, tico.hz, plot=TRUE)
## mel scale
require(tuneR)
orni.mel <- melfcc(orni, nbands = 256, dcttype = "t3", fbtype = "htkmel", spec_out=TRUE)
orni.mel.mean <- apply(orni.mel$aspectrum, MARGIN=2, FUN=mean)
tico.mel <- melfcc(tico, nbands = 256, dcttype = "t3", fbtype = "htkmel", spec_out=TRUE)
tico.mel.mean <- apply(tico.mel$aspectrum, MARGIN=2, FUN=mean)
diffcumspec(orni.mel.mean, tico.mel.mean, f=22050, mel=TRUE, plot=TRUE)