r - 如何 rbind 匹配其列名的向量？

Question

rbind 在将向量绑定(bind)在一起时不检查列名:

l = list(row1 = c(10, 20), row2 = c(20, 10))
names(l$row1) = c("A", "B")
names(l$row2) = c("B", "A")
l
$row1
 A  B 
10 20 

$row2
 B  A 
20 10 

rbind(l$row1, l$row2)
      A  B
[1,] 10 20
[2,] 20 10

如何从多个列表元素中生成此矩阵，以确保列名跨行正确匹配:

      A  B
[1,] 10 20
[2,] 10 20

Answer 1

您可以使用 match :

l <- list(row1 = setNames(1:3, c("A", "B", "C")),
          row2 = setNames(1:3, c("B", "C", "A")),
          row3 = setNames(1:3, c("C", "A", "B")))

do.call(rbind, lapply(l, function(x) x[match(names(l[[1]]), names(x))]))

结果:

     A B C
row1 1 2 3
row2 3 1 2
row3 2 3 1