fund: Fundamental frequency track

Description

This function estimates the fundamental frequency through a short-term cepstral transform.

Usage

fund(wave, f, channel = 1, wl = 512, ovlp = 0, fmax = f/2, threshold = NULL,
at = NULL, from = NULL, to = NULL, 
plot = TRUE, xlab = "Time (s)", ylab = "Frequency (kHz)",
ylim = c(0, f/2000), pb = FALSE, ...)

Value

When plot is FALSE, fund returns a two-column matrix, the first column corresponding to time in seconds (x-axis) and the second column corresponding to to fundamental frequency in kHz (y-axis).

NA corresponds to pause sections in wave (see threshold).

No plot is produced when using at.

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 defaults = 512).
ovlp: overlap between two successive windows (in %).
fmax: the maximum frequency to detect (in Hz).
threshold: amplitude threshold for signal detection (in %).
at: position where the estimate the fundamental frequency (in s)

from: start position where to compute the fundamental frequency (in s).
to: end position to compute the fundamental frequency (in s).
plot: logical, if TRUE plots the fundamental frequency modulations against time (by default TRUE).
xlab: title of the time axis (s).
ylab: title of the frequency axis (Hz).
ylim: the range of frequency values.
pb: if TRUE returns a text progress bar in the console.
...: other plot graphical parameters.

Author

Jerome Sueur sueur@mnhn.fr.

References

Oppenheim, A.V. and Schafer, R.W. 2004. From frequency to quefrency: a history of the cepstrum. Signal Processing Magazine IEEE, 21: 95-106.

Examples

Run this code

data(sheep)
# estimate the fundamental frequency at a single position
fund(sheep, f=8000, fmax=300, at=1, plot=FALSE)
# track the fundamental frequency along time
fund(sheep,f=8000,fmax=300,type="l")
# with 50% overlap between successive sliding windows, time zoom and 
# amplitude filter (threshold)
fund(sheep,f=8000,fmax=300,type="b",ovlp=50,threshold=5,ylim=c(0,1),cex=0.5)
# overlaid on a spectrogram
spectro(sheep,f=8000,ovlp=75,zp=16,scale=FALSE,palette=reverse.gray.colors.2)
par(new=TRUE)
fund(sheep,f=8000,fmax=300,type="p",pch=24,ann=FALSE,
  xaxs="i",yaxs="i",col="black",bg="red",threshold=6)

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