R: Coherence between two time waves

coh {seewave}

R Documentation

Coherence between two time waves

Description

This function returns the frequency coherence between two time waves.

Usage

coh(wave1, wave2, f, channel=c(1,1), plot =TRUE, xlab = "Frequency (kHz)",
ylab = "Coherence", xlim = c(0,f/2000), type = "l",...)

Arguments

`wave1`	a first R object.
`wave2`	a second R object.
`f`	sampling frequency of `wave` (in Hz). Does not need to be specified if embedded in `wave`.
`channel`	channel of the R objects, by default left channel (1) for each object.
`plot`	logical, if `TRUE` plots the continuous coherence function (by default `TRUE`).
`xlab`	title of the frequency X-axis.
`ylab`	title of the coherence Y-axis.
`xlim`	range of frequency X-axis.
`type`	if `plot` is `TRUE`, type of plot that should be drawn. See `plot` for details (by default "l" for lines).
`...`	other `plot` graphical parameters.

Details

Coherence is a frequency domain function computed to show the degree of a relationship between two signals. The value of the coherence function ranges between zero and one, where a value of zero indicates there is no causal relationship between the signals. A value of one indicates the existence of linear frequency response between the two signals. This can be used, for instance, to compare the input and output signals of a system.

Value

When plot is FALSE, this coh returns a two-column matrix, the first column being the frequency axis in kHz (x-axis) and the second column being the coherence (y-axis).

Note

This function is based on spec.pgram.

Author(s)

Jerome Sueur sueur@mnhn.fr but this function is based on spec.pgram by Martyn Plummer, Adrian Trapletti and B.D. Ripley.

Examples

wave1<-synth(d=1,f=4000,cf=500)
wave2<-synth(d=1,f=4000,cf=800)
coh(wave1,wave2,f=4000)

[Package seewave version 2.1.6 Index]