revw {seewave}

Time reverse of a time wave

Description

Reverse the wave along the time axis.

Usage

revw(wave, f, channel = 1, env = TRUE, ifreq = TRUE,
plot = 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).

env

logical, if TRUE the amplitude envelope is reversed.

ifreq

logical, if TRUE the instantaneous frequency is reversed.

plot

logical, if TRUE returns an oscillographic plot of the reversed wave (by default FALSE).

output

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

...

other oscillo graphical parameters.

Details

If plot is TRUE returns an oscillogram of the reversed wave. The amplitude and the instantaneous frequency can be independently reversed thanks to the arguments env and ifreq. See the examples.

Value

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

Author(s)

Jerome Sueur [e-mail]

References

Beeman, K. 1998. Digital signal analysis, editing and synthesis in Hopp, S. L., Owren, M. J. and Evans, C. S. (Eds) 1998. Animal acoustic communication, pp. 59-103. Springer, Berlin, Heidelberg.

See Also

oscillo, addsilw, deletew, fadew, pastew, mutew

Examples

data(tico)
# simple reverse
revw(tico,f=22050,plot=TRUE)
# envelope reverse only
revw(tico,f=22050,ifreq=FALSE, plot=TRUE)
# instantaneous frequency reverse only
revw(tico,f=22050,env=FALSE, plot=TRUE)