afilter {seewave}

Amplitude filter

Description

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

Usage

afilter(wave, f, channel = 1, threshold = 5, plot = TRUE,
listen = FALSE, output = "matrix", ...)

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 (in %).

plot

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

listen

if TRUE the new sound is played back.

output

character string, the class of the object to return, either "matrix", "Wave", "Sample", "audioSample" or "ts".

...

other oscillo graphical parameters.

Details

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

Value

If plot is FALSE, a new wave is returned. The class of the returned object is set with the argument output.

Note

This function is used as an argument (threshold) in the following functions: autoc, csh, dfreq, timer and zc.

Author(s)

Jerome Sueur [e-mail]

See Also

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)