seewave (version 2.1.6)

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, ...)

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.

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.

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.

See Also

cepstro, ceps, autoc

Examples

# NOT RUN {
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)
# }