R: Continuous spectral entropy

csh {seewave}

R Documentation

Continuous spectral entropy

Description

This function computes the continuous spectral entropy (H) of a time wave.

Usage

csh(wave, f, channel = 1, wl = 512, wn = "hanning", ovlp = 0,
fftw = FALSE, threshold = NULL,
plot = TRUE, xlab = "Times (s)", ylab = "Spectral Entropy",
ylim = c(0, 1.1), type = "l", ...)

Arguments

`wave`	an R object.
`f`	sampling frequency of `wave` (in Hz). Does not need to be specified if embedded in `wave`.
`channel`	channel of the R object, by default left channel (1).
`wl`	if `at` is not null, length of the window for the analysis (even number of points, by default = 512).
`wn`	window name, see `ftwindow` (by default `"hanning"`).
`ovlp`	overlap between two successive windows (in %).
`fftw`	if `TRUE` calls the function `FFT` of the library `fftw`. See Notes of the `spectro`.
`threshold`	amplitude threshold for signal detection (in %).
`plot`	logical, if `TRUE` plots the spectral entropy against time (by default `TRUE`).
`xlab`	title of the x axis.
`ylab`	title of the y axis.
`ylim`	the range of y values.
`type`	if `plot` is `TRUE`, type of plot that should be drawn. See `plot` for details (by default "l" for lines).
`...`	other `plot` graphical parameters.

Details

See sh for computing method.

Value

When plot is FALSE, csh returns a two-column matrix, the first column being time in seconds (x-axis) and the second column being the spectral entropy (y-axis) computed along time.
NA corresponds to pause sections in wave (see threshold).

Note

The spectral entropy of a noisy signal will tend towards 1 whereas the spectral entropy of a pure tone signal will tend towards 0.

Author(s)

Jerome Sueur sueur@mnhn.fr

References

Toh, A. M., Togneri, R. & Nordholm, S. 2005 Spectral entropy as speech features for speech recognition. Proceedings of PEECS, pp. 60-65.

Examples

data(orni)
csh(orni,f=22050,wl=512,ovlp=50)
# using the threshold argument can lead to some edge effets
# here sh=1 at the end of echemes
csh(orni,f=22050,wl=512,ovlp=50,threshold=5)

[Package seewave version 2.1.6 Index]