1.Rmd

Chapter 8: Exercise 1
========================================================

```{r label="1"}
par(xpd=NA)
plot(NA, NA, type="n", xlim=c(0,100), ylim=c(0,100), xlab="X", ylab="Y")
# t1: x = 40; (40, 0) (40, 100)
lines(x=c(40,40),y=c(0,100))
text(x=40, y=108, labels=c("t1"), col="red")
# t2: y = 75; (0, 75) (40, 75)
lines(x=c(0,40), y=c(75,75))
text(x=-8, y=75, labels=c("t2"), col="red")
# t3: x = 75; (75,0) (75, 100)
lines(x=c(75,75),y=c(0,100))
text(x=75, y=108, labels=c("t3"), col="red")
# t4: x = 20; (20,0) (20, 75)
lines(x=c(20,20),y=c(0,75))
text(x=20, y=80, labels=c("t4"), col="red")
# t5: y=25; (75,25) (100,25)
lines(x=c(75,100),y=c(25,25))
text(x=70, y=25, labels=c("t5"), col="red")

text(x=(40+75)/2, y=50, labels=c("R1"))
text(x=20, y=(100+75)/2, labels=c("R2"))
text(x=(75+100)/2, y=(100+25)/2, labels=c("R3"))
text(x=(75+100)/2, y=25/2, labels=c("R4"))
text(x=30, y=75/2, labels=c("R5"))
text(x=10, y=75/2, labels=c("R6"))
```

```
        [  X<40 ] 
        |       |
    [Y<75]    [X<75]
    |   |     |    |
 [X<20] R2    R1   [Y<25]
 |    |            |    |
 R6   R5           R4   R3
```