| autoc {seewave} | R Documentation |
This function returns the fundamental frequency of a harmonic time wave. This is achieved by computing a correlation of the signal with itself after a time delay.
autoc(wave, f, wl = 512, fmax, threshold = NULL, plot = TRUE, xlab = "Time (s)", ylab = "Frequency (kHz)", ylim = c(0, f/2000),...)
wave |
a vector, a matrix (first column),
an object of class ts, Sample (left channel),
or Wave (left channel). |
f |
sampling frequency of wave (in Hz).
Does not need to be specified if wave is an object of class ts,
Sample, or Wave. |
wl |
length of the window for the analysis (even number of points, by default = 512). |
fmax |
the maximum frequency to detect (in Hz). |
threshold |
amplitude threshold for signal detection (in %). |
plot |
logical, if TRUE plots the fundamental frequency
against time (by default TRUE). |
xlab |
title of the x-axis. |
ylab |
title of the y-axis. |
ylim |
the range of y values. |
... |
other plot graphical parameters. |
Autocorrelation process can be time consuming.
When plot is FALSE, autoc 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).
Jerome Sueur sueur@mnhn.fr and Thierry Aubin thierry.aubin@u-psud.fr
Hopp, S. L., Owren, M. J. and Evans, C. S. (Eds) 1998. Animal acoustic communication. Springer, Berlin, Heidelberg.
data(sheep)
# fundamental frequency of a sheep
autoc(sheep,f=8000,threshold=5,fmax=700)
# overlay on spectrogram
spectro(sheep,f=8000,ovlp=75,zp=16,scale=FALSE)
par(new=TRUE)
autoc(sheep,f=8000,wl=512,threshold=5,fmax=700,col="black",pch=20,
xaxs="i",yaxs="i",ann=FALSE,yaxt="n")
legend(0.5,3.6,"Fundamental frequency",pch=20,col="black",bty=0,cex=0.7)