diffwave {seewave} | R Documentation |
This function estimates the difference between two waves by computing the product between envelope surface difference and frequency surface difference.
diffwave(wave1, wave2, f, wl = 512, envt = "hil", msmooth = NULL, ksmooth = NULL)
wave1 |
data or a Sample object generated loading a wav file
with loadSample (package sound) describing a first time wave. |
wave2 |
data or a Sample object generated loading a wav file
with loadSample (package sound) describing a second time wave. |
f |
sampling frequency of wave1 and wave1 (in Hz).
Does not need to be specified if wave1 and/or wave2 are/is (a)
Sample object(s). |
wl |
window length for spectral analysis (even number of points). |
envt |
the type of envelope to be used: either "abs" for absolute
amplitude envelope or "hil" for Hilbert amplitude envelope. See env . |
msmooth |
a vector of length 2 to smooth the amplitude envelope with a
mean sliding window. The first component is the window length
(in number of points). The second component is the overlap between
successive windows (in %). See env . |
ksmooth |
kernel smooth via kernel . See env . |
This function computes the product between the values obtained with
diffspec
and diffenv
functions.
This then gives a global (time and frequency) estimation of dissimilarity.
The frequency mean spectrum and the amplitude envelope needed for computing
respectively diffspec
and diffenv
are automatically generated.
They can be controlled through wl
, msmooth
and ksmooth
arguments respectively.
See examples below and examples in diffspec
and diffenv
for implications on the results.
A single value varying between 0 and 1 is returned. The value has no unit.
This method can be used as a relative distance estimation between different waves.
Jerome Sueur sueur@mnhn.fr
Sueur, J., Pavoine, S., Hamerlynck, O. & Duvail, S., in preparation.
data(tico) data(orni) # selection in tico to have two waves of similar duration (length) tico<-as.matrix(tico[1:nrow(orni),1]) diffwave(tico,orni,f=22050) # changing the frequency parameter (wl) diffwave(tico,orni,f=22050,wl=1024) # changing the temporal parameter (msmooth) diffwave(tico,orni,f=22050,msmooth=c(20,0))