Total entropy
This function estimates the total entropy of a time wave.
H(wave, f, channel = 1, wl = 512, envt="hil", msmooth = NULL, ksmooth = NULL)
wave |
an R object. |
f |
sampling frequency of |
channel |
channel of the R object, by default left channel (1). |
wl |
window length for spectral entropy analysis
(even number of points). See |
envt |
the type of envelope to be used: either "abs" for absolute
amplitude envelope or "hil" for Hilbert amplitude envelope. See |
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 |
ksmooth |
This function computes the product between the values obtained with
sh and th functions.
This then gives a global (time and frequency) estimation of signal entropy.
The frequency mean spectrum and the amplitude envelope needed for computing
respectively sh and th are automatically generated.
They can be controlled through wl and smooth arguments respectively.
See examples below and examples in sh and th
for implications on the results.
A single value varying between 0 and 1 is returned. The value has no unit.
The entropy of a noisy signal will tend towards 1 whereas the entropy of a pure tone signal will tend towards 0.
Jerome Sueur sueur@mnhn.fr
Sueur, J., Pavoine, S., Hamerlynck, O. & Duvail, S. (2008) - Rapid acoustic survey for biodiversity appraisal. PLoS ONE, 3(12): e4065.
data(orni) H(orni,f=22050) # changing the spectral parameter (wl) H(orni,f=22050,wl=1024) # changing the temporal parameter (msmooth) H(orni,f=22050,msmooth=c(20,0))
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