seewave (version 1.0)

oscillo: Show a time wave as an oscillogram

Description

This graphical function displays a time wave as an oscillogram in a single or multi-frame plot. The envelope of the wave can also be shown.

Usage

oscillo(wave, f, from = FALSE, to = FALSE, zoom = FALSE,
k=1, j=1, byrow = TRUE, env = FALSE, smooth = 0,
identify = FALSE, plot = TRUE, colwave = "black", 
colbg = "white", coltitle = "black", collab = "black", 
cexlab = 1, fontlab = 1, colline = "black", 
colaxis = "black", coly0 = "grey47",
title = FALSE, bty = "l")

Arguments

wave

data describing a time wave.

f

sampling frequency of wave.

from

start of the oscillogram (in s).

to

end of the oscillogram (in s).

zoom

time zoom in with start and end points chosen on the oscillogram with a cursor.

k

number of horizontal sections (by default =1).

j

number of vertical sections (by default =1).

byrow

logical, if TRUE, the sections are filled by rows, otherwise the sections are filled by colmuns (by default TRUE).

env

logical, if TRUE plots the envelope of the time wave instead (by default FALSE).

smooth

if env is TRUE then smoothes the envelope by averaging the number of points selected.

identify

returns the time coordinate of points chosen on the oscillogram with a cursor.

plot

logical, if TRUE returns an oscillographic or envelope plot of wave(by default TRUE).

colwave

colour of the oscillogram or of the envelope.

colbg

background colour.

coltitle

if title is TRUE, colour of the title.

cexlab

character size for axes title.

fontlab

font for axes title.

collab

colour of axes title.

colline

colour of axes line.

colaxis

colour of the axes.

coly0

colour of the y=0 line.

title

logical, if TRUE plots the title with information on time and f (by default FALSE).

bty

the type of box to be drawn around the oscillogram.

Value

• Data are returned as one-column matrix if plot is FALSE. identify returns a numeric object with the time coordinate of points successively chosen on the oscillogram.

See Also

cutw, pastew, timer.

Examples

data(tico)
# a simple oscillogram of a bird song
oscillo(tico,f=22050)
# zoom in
op<-par(mfrow=c(4,1),mar=c(4.5,4,2,2))
oscillo(tico,22050,cexlab=0.75)
oscillo(tico,22050,from=0.5,to=0.9,cexlab=0.75)
oscillo(tico,22050,from=0.65,to=0.75,cexlab=0.75)
oscillo(tico,22050,from=0.68,to=0.70,cexlab=0.75)
par(op)
# the same divided in four lines
oscillo(tico,f=22050,k=4,j=1)
# the same divided in different numbers of lines and columns
oscillo(tico,f=22050,k=4,j=4)
oscillo(tico,f=22050,k=2,j=2,byrow=TRUE)
oscillo(tico,f=22050,k=2,j=2,byrow=FALSE)
# envelope representation without and with smoothing
oscillo(tico,f=22050,env=TRUE)
oscillo(tico,f=22050,env=TRUE,smooth=80)
# overplot of oscillographic and envelope representation
env<-oscillo(tico,f=22050,env=TRUE,plot=FALSE,smooth=40)
ticonorm<-tico/max(tico)
envnorm<-env/max(env)
oscillo(ticonorm,f=22050)
par(new=TRUE)
plot(envnorm,type="l",col="red",xaxs="i",yaxs="i",ann=FALSE,xaxt="n",yaxt="n",
    ylim=range(ticonorm),bty="l",lwd=2)
legend(x=4, y=1,"smoothed envelope", col="red",lty=1,lwd=2,bty="n",cex=0.75)
# full colour modifications in a two-frame oscillogram
oscillo(tico,f=22050,k=4,j=1,title=TRUE,colwave="black",colbg="grey",
    coltitle="yellow",collab="red",colline="white",
    colaxis="blue",coly0="grey50")
# change the title
data(orni)
oscillo(orni,f=22050,title=FALSE)
mtext("The song of a famous cicada",side=3,line=2,font=2,col="red",cex=1.5)