drawenv {seewave} | R Documentation |
This function lets the user modifying the amplitude envelope of a time wave by drawing it with the graphics device
drawenv(wave, f, n = 20, plot = FALSE, listen = FALSE, output = "matrix")
wave |
an R object. |
f |
sampling frequency of wave (in Hz). Does not need to be specified if embedded in wave . |
n |
the maximum number of points to draw the new envelope. Valid values start at 1. |
plot |
if TRUE returns the oscillogram
of the new time wave (by default FALSE ). |
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" . |
The function first plots an oscillogram view of wave
.
The user has then to choose points on the positive side of the y-axis (amplitude).
The junction of these points will draw a new amplitude envelope.
The order of points along the x-axis (time) is not important
but points cannot be cancelled. When this process is finished
the new time wave is returned in the console or as an oscillogram
in a second graphics device if plot
is TRUE
.
The function uses locator
.
If plot
is FALSE
, a new wave is returned. The class
of the returned object is set with the argument output
.
Jerome Sueur sueur@mnhn.fr
a<-synth(d=1,f=22050,cf=1000) # drawenv(a,f=22050,plot=TRUE) # choose points on the oscillogram view to draw a new enveloppe # stop (ESC on Windows; right mouse button on Linux) # check the result on the second graphics device opened thanks to plot=TRUE