Plotting several variables on the same scale in R

Question

I've tried over and over to solve this issue but I can't get it down. I have estimated a Beta-t-EGARCH model and a GARCH-t model in R and now I need to plot the results over the same plot. The final result is horrible, since the variables don't share the same scale on the y axis. I'm new to R, so please don't blame me :). Here's the code:

library(quantmod)
library(betategarch)
library(fGarch)
library(ggplot2)

getSymbols("GOOG",src="yahoo")
google_ret <- abs(periodReturn(GOOG, period="daily", subset=NULL, type="log"))-mean(abs(periodReturn(GOOG, period="daily", subset=NULL, type="log")))

googcomp <- tegarch(google_ret, asym=FALSE, skew=FALSE)
goog1stdev <- fitted(googcomp)


#now we try to fit a standard GARCH-t model
googgarch <- garchFit(data=google_ret, cond.dist="sstd")
googgarch2 <- garchFit(data=google_ret, cond.dist="sstd", include.mean = FALSE, include.delta = FALSE, include.skew = FALSE, include.shape = FALSE, leverage = FALSE, trace = TRUE)
volatility <- volatility(googgarch2, type = "sigma") 


plot(google_ret)
par(new=TRUE)
plot(googgarch2, which=2)
par(new=TRUE)
plot(goog1stdev, col="red")

The final result is a plot completely out of scale on the y axis, with variables that have lower values plotted above higher ones. Thanks a lot to anybody that wants to help me!

Answer 1

The recommended approach is to plot them as different plots stacked on top of each other:

layout(matrix(1:3,3))
plot(google_ret)
plot(googgarch2, which=2)
plot(goog1stdev, col="red")

You can get rid of the whitespace with calls to par("mar") to adjust margin sizes:

 opar=par(mar=par("mar") -c(1,0,3,0))  # opar will then let your restore previous values
 ..... plotting efforts
 par(opar)

I don't know your domain very much but if you cna use shifted y-ordinates then this produces a somewhat cleaned up version with overlayed plots:

png()
plot(google_ret, ylim=c(0,1), ylab="ylab="Google Returns(black); GGarch x10 +0.5 (blue); STD + 0.3(red)" )
par(new=TRUE)
plot(googgarch2@data +.5, type="l", col="blue",axes=FALSE,  ylab="", main="",ylim=c(0, 1)) ;abline(h=.5, col="blue")
par(new=TRUE);
plot( 10*coredata(goog1stdev) + .3, col="red", type="l", axes=FALSE, main="",ylim=c(0,1), ylab=""); abline(h=.3, col="red")
dev.off()