如何將 R 資料框中的兩列轉換為命名向量?
如果兩列的形式是,一列包含向量值的名稱,另一列包含向量的值,那麼我們可能希望將它們轉換為一個向量。為此,我們可以簡單地讀取具有其資料型別和結構的向量,並使用結構函式對它們進行結構化。
示例 1
x1<-rep(c("C1","C2","C3","C4"),each=5)
x2<-rep(1:10,2)
df1<-data.frame(x1,x2)
df1輸出
x1 x2 1 C1 1 2 C1 2 3 C1 3 4 C1 4 5 C1 5 6 C2 6 7 C2 7 8 C2 8 9 C2 9 10 C2 10 11 C3 1 12 C3 2 13 C3 3 14 C3 4 15 C3 5 16 C4 6 17 C4 7 18 C4 8 19 C4 9 20 C4 10 df1_vector<-structure(as.numeric(df1$x2),names=as.character(df1$x1)) df1_vector C1 C1 C1 C1 C1 C2 C2 C2 C2 C2 C3 C3 C3 C3 C3 C4 C4 C4 C4 C4 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10
示例 2
set.seed(111) y1<-LETTERS[1:20] y2<-rnorm(20,0.5) df2<-data.frame(y1,y2) df2
輸出
y1 y2 1 A 0.735220712 2 B 0.169264128 3 C 0.188376176 4 D -1.802345658 5 E 0.329123955 6 F 0.640278225 7 G -0.997426656 8 H -0.510188419 9 I -0.448475605 10 J 0.006037783 11 K 0.326325872 12 L 0.093401220 13 M 2.345636264 14 N 0.894054110 15 O 1.297528501 16 P -1.066665360 17 Q 0.414148991 18 R 0.140860519 19 S -0.693608967 20 T 0.864186737 df2_vector<-structure(as.numeric(df2$y2),names=as.character(df2$y1)) df2_vector A B C D E F 0.735220712 0.169264128 0.188376176 -1.802345658 0.329123955 0.640278225 G H I J K L -0.997426656 -0.510188419 -0.448475605 0.006037783 0.326325872 0.093401220 M N O P Q R 2.345636264 0.894054110 1.297528501 -1.066665360 0.414148991 0.140860519 S T -0.693608967 0.864186737
示例 3
z1<-rep(c("String1","String2","String3","String4","String5"),each=4)
z2<-letters[20:1]
df3<-data.frame(z1,z2)
df3輸出
z1 z2 1 String1 t 2 String1 s 3 String1 r 4 String1 q 5 String2 p 6 String2 o 7 String2 n 8 String2 m 9 String3 l 10 String3 k 11 String3 j 12 String3 i 13 String4 h 14 String4 g 15 String4 f 16 String4 e 17 String5 d 18 String5 c 19 String5 b 20 String5 a df3_vector<-structure(as.character(df3$z2),names=as.character(df3$z1)) df3_vector String1 String1 String1 String1 String2 String2 String2 String2 String3 String3 "t" "s" "r" "q" "p" "o" "n" "m" "l" "k" String3 String3 String4 String4 String4 String4 String5 String5 String5 String5 "j" "i" "h" "g" "f" "e" "d" "c" "b" "a"
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