##### R-code for making Figure 7.2 to demonstrate the Scan method

x1 = seq(30,70)/100
y1 = 0.5+sqrt(0.2^2-(x1-0.5)^2)
y2 = 0.5-sqrt(0.2^2-(x1-0.5)^2)

x2 = c(20.05,seq(21,39),39.97)/100
z1 = 0.5+sqrt(0.1^2-(x2-0.3)^2)
z2 = 0.5-sqrt(0.1^2-(x2-0.3)^2)

set.seed(10)

s1 = runif(50,0,1)
s2 = runif(50,0,1)
s3 = c(rep(0.35,5),rep(0.4,10),rep(0.45,15),rep(0.5,20),
       rep(0.55,15),rep(0.6,10),rep(0.65,5))
s4 = c(runif(5,0.5-sqrt(0.2^2-0.15^2),0.5+sqrt(0.2^2-0.15^2)),
       runif(10,0.5-sqrt(0.2^2-0.1^2),0.5+sqrt(0.2^2-0.1^2)),
       runif(15,0.5-sqrt(0.2^2-0.05^2),0.5+sqrt(0.2^2-0.05^2)),
       runif(20,0.3,0.7),
       runif(15,0.5-sqrt(0.2^2-0.05^2),0.5+sqrt(0.2^2-0.05^2)),
       runif(10,0.5-sqrt(0.2^2-0.1^2),0.5+sqrt(0.2^2-0.1^2)),
       runif(5,0.5-sqrt(0.2^2-0.15^2),0.5+sqrt(0.2^2-0.15^2)))

pdf("fig72.pdf",width=4,height=4.5)

plot(x1,y1,type="l",lty=1,xlab="",ylab="",xaxt="n",yaxt="n",
     mgp=c(0,0,0),xlim=c(0,1),ylim=c(0,1),cex=0.8)
points(c(s1,s3),c(s2,s4),pch=".",cex=0.8)
lines(x1,y2,lty=1,cex=0.8)
lines(x2,z1,lty=2,cex=0.8)
lines(x2,z2,lty=2,cex=0.8)
text(0.9,0.1,"G",cex=1)
text(0.6,0.5,"Z",cex=1)
text(0.24,0.5,"A",cex=1)

graphics.off()