R: Hilbert transform and analytic signal

hilbert {seewave}

R Documentation

Hilbert transform and analytic signal

Description

This function returns the analytic signal of a time wave through Hilbert transform.

Usage

hilbert(wave, f, channel = 1, fftw = FALSE)

Arguments

`wave`	an R object.
`f`	sampling frequency of `wave` (in Hz). Does not need to be specified if embedded in `wave`.
`channel`	channel of the R object, by default left channel (1).
`fftw`	if `TRUE` calls the function `FFT` of the library `fftw` for faster computation. See Notes of the function `spectro`.

Details

The analytic signal is useful to get the amplitude envelope (see argument henv of oscillo and the instantaneous phase or frequency (see ifreq) of a time wave.

Value

hilbert returns the analytic signal as a complex matrix. The imaginary part of this matrix is the Hilbert transform.

Note

To get the Hilbert component only, use Im(Hilbert(wave)).

Author(s)

Jonathan Lees jonathan.lees@unc.edu. Implementation of 'fftw' argument by Jean Marchal and Francois Fabianek.

References

Mbu Nyamsi, R. G., Aubin, T. & Bremond, J. C. 1994 On the extraction of some time dependent parameters of an acoustic signal by means of the analytic signal concept. Its application to animal sound study. Bioacoustics, 5: 187-203.

Examples

a<-synth(f=8000, d=1, cf=1000)
aa<-hilbert(a, f=8000)

[Package seewave version 2.1.6 Index]