如何按目标向量给定的列值重新排序数据框

Question

我有一个这样的矩阵：

structure(c("A1", "B", "C", "A1", "A2", "C", "1", "2", "3", "4", 
"5", "6"), .Dim = c(6L, 2L))

我想使用目标向量

target <- c("A1","A2", "B", "C")

对行重新排序并获得这样的数据帧：

"A1" "1" 
"A1" "4"
"A2" "5"
"B"  "2" 
"C"  "3" 
"C"  "6" 

Answer 1

我们可以对数据集的第一列和“目标”向量之间的match使用order

df1[order(match(df1[,1], target)),]

-输出

#     [,1] [,2]
#[1,] "A1" "1" 
#[2,] "A1" "4" 
#[3,] "A2" "5" 
#[4,] "B"  "2" 
#[5,] "C"  "3" 
#[6,] "C"  "6" 

---

或者另一种选择是将第一列的levels设置为“目标”并order

df1[order(factor(df1[,1], levels = target)),]