seewave (version 2.1.6)

specflux: Spectral flux

Description

Compute spectral flux

Usage

specflux(wave, f, channel = 1,
         wl = 512, ovlp = 0, wn = "rectangle", flim = NULL,
         norm = FALSE,  p = 2,
         plot = TRUE, xlab = "Times (s)", ylab = "Flux", 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

window length for the analysis (even number of points) (by default = 512).

ovlp

overlap between two successive windows (in %).

wn

window name, see ftwindow (by default "rectangle").

flim

a numeric vector of length 2 to select a frequency band (in kHz).

norm

if is TRUE then the normalised spectra are used. The spectra are normalised by their sum.

p

the norm type, by default = 2.

plot

logical, if TRUE the spectral flux is displayed against time (s) (by default TRUE).

xlab

title of the x axis.

ylab

title of the y axis.

type

if plot is TRUE, type of plot that should be drawn. See plot for details (by default "l" for lines).

…

other plot parameters.

Value

When plot is FALSE, specflux returns a two-column matrix, the first column being time in seconds (x-axis) and the second column being the spectral flux (y-axis) computed along time.

Details

The spectral flux (\(F\)) is the sum of the time (\(t\)) derivative of the columns -- that is the successive spectra -- (\(s\)) of the normalized short-term Fourier transform (\(z\)). F is then computed according to: $$F = (\sum |s(t+1) - s(t)|^{p})^{\frac{1}{p}}$$

References

Scheirer E, Slaney M (1997). Construction and evaluation of a robust multifeature speech/music discriminator. IEEE International Conference on Acoustics, Speech, and Signal Processing, 2, 1221-1224.

See Also

spectro, ACI

Examples

# NOT RUN {
## default use
data(tico)
specflux(tico)
## norm 1
specflux(tico, p = 1)
## frequency limit between 2 and 4 kHz
specflux(tico, flim = c(2,4))
## index computation
sum(specflux(tico, plot=FALSE)[,2])
# }