seewave (version 1.7.6)

coh: Coherence between two time waves

Description

This function returns the frequency coherence between two time waves.

Usage

coh(wave1, wave2, f, 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.

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.

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).

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.

See Also

ccoh, spectro, spec.pgram.

Examples

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