> # Printing plots
> ?device
> pdf()
> plot(Exam1,Exam2, main="Scatterplot", type="l",xlab="1st Exam", ylab="2nd Exam")
> dev.off()
X11cairo 
       2 

> postscript()
> plot(Exam1,Exam2, type="p")

> jpeg()
> plot(Exam1,Exam2, type="p")
> dev.off()

> system("ls")

> dev.list()                 # open devices
X11cairo     jpeg 
       2        3 

> dev.cur()                  # current active device
> dev.set(3)                 # set new active
jpeg 
   3 
> dev.cur()
jpeg 
   3 
> dev.off()
X11cairo 
       2 
> dev.cur()
X11cairo 
       2 

>  # More Plots

> dotchart(grades)
> dotchart(grades[,4:8])
> grades2<-cbind(Exam1,Exam2,Final)
> dotchart(grades2)
> hist(Exam1)
> plot(Exam1, Exam2)
> plot(Exam1, Exam2, pch=22)
> plot(Exam1, Exam2, pch=22, col="red")
> plot(Exam1, Exam2, pch=22, col="red", bg="yellow")
> plot(Exam1, Exam2, pch=22, col="red", bg="yellow",xlim=c(50,100),ylim=c(50,100))

> # Change graphing parameters (beyond arguments in plot command)

> opar<-par()    # save default parameters
> par(bg="lightyellow", col.axis="blue")
> plot(Exam1, Exam2, pch=22, col="red", bg="yellow",xlim=c(50,100),ylim=c(50,100))
> par(opar)      # Back to default

> # Low level plotting commands  (adds to current graph)
> plot(Exam1,Exam2)
> abline(0,1)
> plot(Exam1,Exam2)
> segments(40,60,100,100)
> abline(h=80)
> abline(v=80)
> legend(70,52,"Outlier")
> title("Test Plot")

> #### T-DENSITY WITH SHADED TAILS
> x<-seq(-3.5,3.5,by=.1)
> y<-dt(x,100)
> plot(x,y,type="l",xlab="t",ylab="f(t)")
> a<-c(seq(1.7,3.5,by=.1),seq(3.5,1.7,by=-.1))
> a
 [1] 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.5 3.4
[22] 3.3 3.2 3.1 3.0 2.9 2.8 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2.0 1.9 1.8 1.7
> b<-dt(a,100)
> b[20:38]=0
> b
 [1] 0.094401610 0.079524428 0.066380394 0.054908643 0.045014094 0.036577181 0.029462833
 [8] 0.023528353 0.018630004 0.014628231 0.011391541 0.008799144 0.006742523 0.005126090
[15] 0.003867144 0.002895306 0.002151587 0.001587248 0.001162555 0.000000000 0.000000000
[22] 0.000000000 0.000000000 0.000000000 0.000000000 0.000000000 0.000000000 0.000000000
[29] 0.000000000 0.000000000 0.000000000 0.000000000 0.000000000 0.000000000 0.000000000
[36] 0.000000000 0.000000000 0.000000000
> #### POLYGON SHADES REGION INSIDE GIVEN COORDINATES
> polygon(a, b,  col = "gray")
> a<-c(seq(-3.5,-1.7,by=.1),seq(-1.7,-3.5,by=-.1))
> b<-dt(a,100)
> b[20:38]=0
> polygon(a, b,  col = "gray")
> #### MTEXT WRITES TEXT ON MARGINS
> mtext("|t_obs|",side=1,at=c(1.7),cex=.7)