Amplitude envelope of a time wave
This function returns the absolute or Hilbert amplitude envelope of a time wave.
env(wave, f, channel = 1, envt = "hil", msmooth = NULL, ksmooth = NULL, ssmooth = NULL, asmooth = NULL, fftw = FALSE, norm = FALSE, plot = TRUE, k = 1, j = 1, ...)
wave |
an R object. |
f |
sampling frequency of |
channel |
channel of the R object, by default left channel (1). |
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 |
ssmooth |
length of the sliding window used for a sum smooth. |
asmooth |
length of the sliding window used for an autocorrelation smooth. |
fftw |
if |
norm |
a logical, if |
plot |
logical, if |
k |
number of horizontal sections when |
j |
number of vertical sections when |
... |
other |
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. Implementation of 'fftw' argument by Jean Marchal and Francois Fabianek. Implementation of 'asmooth' by Thibaut Marin-Cudraz.
data(tico)
# Hilbert amplitude envelope
env(tico)
# absolute amplitude envelope
env(tico, envt="abs")
# smoothing with a 10 points and 50% overlaping mean sliding window
env(tico, msmooth=c(10,50))
# smoothing kernel
env(tico, ksmooth=kernel("daniell",10))
# sum smooth
env(tico, ssmooth=50)
# autocorrelation smooth
env(tico, asmooth=50)
# overplot of oscillographic and envelope representations
oscillo(tico)
par(new=TRUE)
env(tico, colwave=2)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.