資料匯入、檢視資料

dta <- read.table("/Users/User/Desktop/DM_R/hk0413/inclass/inclass2/cigarettes.txt", header=T , stringsAsFactor=F, fill=T )
dim(dta)
## [1] 11  3
str(dta)
## 'data.frame':    11 obs. of  3 variables:
##  $ Country    : chr  "Australia" "Canada" "Denmark" "Finland" ...
##  $ consumption: int  480 500 380 1100 1100 230 490 250 300 510 ...
##  $ death      : int  180 150 170 350 460 60 240 90 110 250 ...
dta
##        Country consumption death
## 1    Australia         480   180
## 2       Canada         500   150
## 3      Denmark         380   170
## 4      Finland        1100   350
## 5           UK        1100   460
## 6      Iceland         230    60
## 7  Netherlands         490   240
## 8       Norway         250    90
## 9       Sweden         300   110
## 10 Switzerland         510   250
## 11         USA        1300   200

繪圖

#plot畫圖，text調整點呈現(預設用數字呈現點)，type 圖的呈現狀態，labels數字呈現轉成代號呈現，cex 點的大小，lty虛線狀態

plot(death ~ consumption, data = dta, type = "n",ylab = "Death rate (per capita) ", xlab = "Cigarettes consumption (per million)",main = 'Ling Cancer and Cigarette Consumption')
text(dta$consumption,dta$death,  labels = dta$Country, cex = .5)
abline(lm(death ~ consumption, data = dta), lty = 2)
grid()