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, fmin, threshold = FALSE, plot = TRUE, xlab = "Time (s)", ylab = "Frequency (kHz)", ylim = c(0, f/2000), ...)
wave |
data describing a time wave
or a Sample object created loading a wav file
with loadSample (package Sound). |
f |
sampling frequency of wave (in Hz). |
wl |
length of the window for the analysis (even number of points). |
fmin |
the minimum 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.
If plot
is FALSE
, autoc
returns a vector of numeric data
describing the fundamental frequency in kHz. NA corresponds
to pause sections in the signal (see threshold
).
Jérôme Sueur jerome.sueur@univ-tours.fr and Thierry Aubin thierry.aubin@ibaic.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,wl=512,t=5,fmin=700) # overlay on spectrogram spectro(sheep,f=8000,wl=512,ovlp=75,zp=16,scale=FALSE) par(new=TRUE) autoc(sheep,f=8000,wl=512,t=5,fmin=700,type="p",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)