支線任務-1

如果我今天是個處理文書的小弟
收到老闆的命令 : 把所有乘客的單獨取出來 , 做成一份檔案
那這時我該怎麼做呢?

可以先大至上找到欄位 : Name 的共通性 -> 在名子後方都會有一個 "," 符號

這時候我們就可以使用GREP套件 快速處理

首先我們先找出 "," 的位置

point = regexpr(",",raw$Name)

> regexpr(",",raw$Name)
  [1]  7  8 10  9  6  6  9  8  8  7 10  8 12 10  8  8  5  9 14 11  7  8  8  7  8  8  5  8
 [29]  8  9 10  8  6  8  6 10  6  5 14 14  6  7  7  8  8  7  7 11  7 15  7 10  7 11  6  8

找出每個字串點的位置之後
來將我們想要的字串取出

substr(raw$Name,1,point)

[883] "Dahlberg,"               "Banfield,"               "Sutehall,"              
[886] "Rice,"                   "Montvila,"               "Graham,"                
[889] "Johnston,"               "Behr," 

目前看起來差了一點 , 多取了一個位置

substr(raw$Name,1,point-1)

完美取出!

[871] "Balkic"                 "Beckwith"               "Carlsson"              
[874] "Vander Cruyssen"        "Abelson"                "Najib"                 
[877] "Gustafsson"             "Petroff"                "Laleff"                
[880] "Potter"                 "Shelley"                "Markun"                
[883] "Dahlberg"               "Banfield"               "Sutehall"              
[886] "Rice"                   "Montvila"               "Graham"                
[889] "Johnston"               "Behr"                   "Dooley"     

當然我們可以貼心一點 , 把這些名字按照字母順序排序

all_name = substr(raw$Name,1,point-1)

提供兩個做法 :

all_name[order(all_name)]

sort(all_name)

交卷~