通過相似的名稱重組Dataframe列

Question

這是我的數據框：

df<-as.data.frame(matrix(rexp(200, rate=.1), ncol=20))
colnames(df)<-c("one","two","three","four","five","six","seven","eight","nine","ten","one_new","two_new","three_new","four_new","five_new","six_new","seven_new","eight_new","nine_new","ten_new")

如何更改此數據框列的位置以具有如下輸出：

One | One_new | two | two_new | three | three_new|.....|ten | ten_new

有什么幫助嗎？

Answer 1

一種長方法是考慮使用starts_with select助手。 您的情況是，您希望以相同術語（例如，“一個”）開頭的列和具有相同術語但又帶有后綴（“新”）的另一列彼此相鄰放置。 starts_with通過捕獲名稱以相同術語開頭的列（例如，以“ one”開頭的列包括“ one”和“ one_new”列）並按此順序排列來做到這一點。

df2 <- df %>%
  select(starts_with("one"), starts_with("two"), starts_with("three"), starts_with("four"),
     starts_with("five"), starts_with("six"), starts_with("seven"), starts_with("eight"),
     starts_with("nine"), starts_with("ten"))

Answer 2

您可以使用所需的列順序創建一個新的數據框

df2<-df[c("one","One_new","two","two_new","three","three_new","ten","ten_new")]

或使用索引：

df2<-df[c(1,11,2,12,3,13...)] #so on.

Answer 3

您可以使用以下代碼來操縱列名的順序。

df[, as.vector(t(matrix(colnames(df), ncol = 2)))]

或操縱列索引

df[, as.vector(t(matrix(1:20, ncol = 2)))]

或在向量中定義順序（ cols ），然后使用lapply和grep檢索列名。

cols <- c("one","two","three","four","five","six","seven","eight","nine","ten")

df[, unlist(lapply(cols, function(x) grep(x, colnames(df), value = TRUE)))]