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法律研究如何在 R 中从数据框值创建字符向量？
要创建 R 中的字符向量，我们可以将向量值置于双引号中，但如果我们想要使用数据框值来创建字符向量，就可以使用 as.character 函数。例如，如果我们有一个数据框 df，那么 df 中的所有值都可以使用 as.character(df[]) 形成一个字符向量。
范例 1
x1<−letters[1:10] x2<−letters[11:20] df1<−data.frame(x1,x2) df1
输出
x1 x2 1 a k 2 b l 3 c m 4 d n 5 e o 6 f p 7 g q 8 h r 9 i s 10 j t as.character(df1[]) [1] "c(\"a\", \"b\", \"c\", \"d\", \"e\", \"f\", \"g\", \"h\", \"i\", \"j\")" [2] "c(\"k\", \"l\", \"m\", \"n\", \"o\", \"p\", \"q\", \"r\", \"s\", \"t\")" is.vector(as.character(df1[])) [1] TRUE
范例 2
set.seed(3232) y1<−sample(LETTERS[1:5],20,replace=TRUE) y2<−sample(LETTERS[6:15],20,replace=TRUE) y3<−sample(LETTERS[16:26],20,replace=TRUE) df2<−data.frame(y1,y2,y3) df2
输出
y1 y2 y3 1 E O U 2 B N U 3 C L P 4 A N Q 5 A I W 6 E M Y 7 E N P 8 B I Z 9 A G Z 10 B J W 11 D L R 12 D G R 13 B M U 14 D K W 15 B F S 16 A O Y 17 D K Z 18 A N Y 19 A O U 20 D K W as.character(df2[]) [1] "c(\"E\", \"B\", \"C\", \"A\", \"A\", \"E\", \"E\", \"B\", \"A\", \"B\", \"D\", \"D\", \"B\", \"D\", \"B\", \"A\", \"D\", \"A\", \"A\", \"D\")" [2] "c(\"O\", \"N\", \"L\", \"N\", \"I\", \"M\", \"N\", \"I\", \"G\", \"J\", \"L\", \"G\", \"M\", \"K\", \"F\", \"O\", \"K\", \"N\", \"O\", \"K\")" [3] "c(\"U\", \"U\", \"P\", \"Q\", \"W\", \"Y\", \"P\", \"Z\", \"Z\", \"W\", \"R\", \"R\", \"U\", \"W\", \"S\", \"Y\", \"Z\", \"Y\", \"U\", \"W\")" is.vector(as.character(df2[])) [1] TRUE
范例 3
z1<−sample(c("Purity","Impurity","Crystal"),20,replace=TRUE)
z2<−sample(c("Chain Reaction","Odorless","Reactive"),20,replace=TRUE)
df3<−data.frame(z1,z2)
df3输出
z1 z2 1 Impurity Reactive 2 Crystal Reactive 3 Impurity Chain Reaction 4 Purity Chain Reaction 5 Impurity Chain Reaction 6 Crystal Reactive 7 Crystal Chain Reaction 8 Impurity Reactive 9 Purity Odorless 10 Impurity Chain Reaction 11 Purity Odorless 12 Purity Chain Reaction 13 Impurity Odorless 14 Impurity Chain Reaction 15 Impurity Odorless 16 Purity Odorless 17 Impurity Chain Reaction 18 Crystal Reactive 19 Impurity Chain Reaction 20 Crystal Reactive as.character(df3[]) [1] "c(\"Impurity\", \"Crystal\", \"Impurity\", \"Purity\", \"Impurity\", \"Crystal\", \"Crystal\", \"Impurity\", \"Purity\", \"Impurity\", \"Purity\", \"Purity\", \"Impurity\", \"Impurity\", \"Impurity\", \"Purity\", \"Impurity\", \"Crystal\", \"Impurity\", \"Crystal\")" [2] "c(\"Reactive\", \"Reactive\", \"Chain Reaction\", \"Chain Reaction\", \"Chain Reaction\", \"Reactive\", \"Chain Reaction\", \"Reactive\", \"Odorless\", \"Chain Reaction\", \"Odorless\", \"Chain Reaction\", \"Odorless\", \"Chain Reaction\", \"Odorless\", \"Odorless\", \"Chain Reaction\", \"Reactive\", \"Chain Reaction\", \"Reactive\")" is.vector(as.character(df3[])) [1] TRUE
更新时间： 2020 年 11 月 7 日
3K+ 次浏览
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