env {seewave} | R Documentation |
This function returns the absolute or Hilbert amplitude envelope of a time wave.
env(wave, f, envt = "hil", msmooth = NULL, ksmooth = NULL, plot = TRUE, k = 1, j = 1, ...)
wave |
data describing a time wave
or a Sample object generated loading a wav file
with loadSample (package sound). |
f |
sampling frequency of wave (in Hz).
Does not need to be specified if wave is a Sample object. |
envt |
the type of envelope to be returned: either "abs" for absolute amplitude envelope or "hil" for Hilbert amplitude envelope. See Details section. |
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 examples. |
ksmooth |
kernel smooth via kernel . See examples. |
plot |
logical, if TRUE returns a plot
of wave envelope (by default TRUE ). |
k |
number of horizontal sections when plot is TRUE
(by default =1). |
j |
number of vertical sections when plot is TRUE
(by default =1). |
... |
other oscillo graphical parameters. |
When envt
is set as "abs", the amplitude envelope returned
is the absolute value of wave
.
When envt
is set as "hil", the amplitude envelope returned is the modulus
(Mod
) of the analytical signal of wave
obtained through the Hilbert transform (hilbert
).
Data are returned as one-column matrix when plot
is FALSE
.
Be aware that smoothing with either msmooth
or ksmooth
changes the original number of points describing wave
.
Jerome Sueur sueur@mnhn.fr
data(tico) # Hilbert amplitude envelope env(tico,f=22050) # absolute amplitude envelope env(tico,f=22050,envt="abs") # smoothing with a 10 points and 50 env(tico,f=22050,msmooth=c(10,50)) # smoothing kernel env(tico,f=22050,ksmooth=kernel("daniell",10)) # overplot of oscillographic and envelope representations oscillo(tico,f=22050) par(new=TRUE) env(tico,f=22050,colwave=2)