seewave (version 1.5.2)

afilter: Amplitude filter

Description

This function deletes all signal which amplitude is below a selected threshold.

Usage

afilter(wave, f, threshold = 5, plot = TRUE,
listen = FALSE, Sample = FALSE,...)

Arguments

wave

a vector, a matrix (first column), an object of class ts, Sample (left channel), or Wave (left channel).

f

sampling frequency of wave (in Hz). Does not need to be specified if wave is an object of class ts, Sample, or Wave

threshold

amplitude threshold (in %).

plot

logical, if TRUE plots the new oscillogram (by default TRUE).

listen

if TRUE the new sound is played back.

Sample

if TRUE and plot is FALSE returns an object of class Sample

...

other oscillo graphical parameters.

Value

• If plot is FALSE, a new wave is returned as a one-column matrix or as a Sample object if Sample is TRUE.

Details

The threshold value is in % relative to the maximal value of wave. Signal inferior to this value is clipped.

See Also

ffilter, oscillo

Examples

data(orni)
op<-par(mfrow=c(2,1))
afilter(orni,f=22050)
title(main = "threshold level = 5")
afilter(orni,f=22050,threshold=0.5,colwave="blue")
title(main = "threshold level = 0.5")
par(op)