seewave (version 1.6.3)

lfs: Linear Frequency Shift

Description

This function linearly shifts all the frequency content of a time wave.

Usage

lfs(wave, f, shift, wl = 128, wn = "hanning", fftw = FALSE, output = "matrix")

Value

• If plot is FALSE, a new wave is returned. The class of the returned object is set with the argument output.

Details

A short-term Fourier transform is first applied to the signal (see spectro), then the frequency shift is applied and the new signal is eventually generated using the reverse of the Fourier Transform (fft). There is therefore neither temporal modifications nor amplitude modifications.

References

Hopp, S. L., Owren, M. J. and Evans, C. S. (Eds) 1998. Animal acoustic communication. Springer, Berlin, Heidelberg.

See Also

ffilter, spectro

Examples

data(orni)
a<-lfs(orni,f=22050,shift=1000)
spectro(a,f=22050)
# to be compared with the original signal
spectro(orni,f=22050)