R: Frequency modulation analysis

fma {seewave}

R Documentation

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 sueur@mnhn.fr

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)

[Package seewave version 2.1.6 Index]