fma {seewave}

Frequency modulation analysis

Description

This function computes the Fourier analysis of the instantaneous frequency of a time wave. This allows to detect periodicity in frequency modulation.

Usage

fma(wave, f, channel = 1, threshold = NULL, plot = TRUE, ...)

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).

threshold

amplitude threshold for signal detection (in % ).

plot

logical, if TRUE the spectrum of the instantaneous frequency (by default TRUE).

...

other spec parameters.

Details

This function is based on ifreq and spec.
The instantaneous frequency of wave is first computed and the spectrum of this frequency modulation is then processed. All env and spec arguments can be set up.

Value

If plot is FALSE, fma returns a numeric vector corresponding to the computed spectrum. If peaks is not NULL, fma returns a list with two elements:

spec

the spectrum computed

peaks

the peaks values (in kHz).

Author(s)

Jerome Sueur [e-mail]

See Also

ifreq, hilbert, spec, ama

Examples

# a sound with a 1 kHz sinusoid FM
a<-synth(d=1, f=8000, cf=1500, fm=c(1000,1000,0,0,0), output="Wave")
fma(a)