R按索引字符串排序字符串

Question

我想按字符串索引

对矩阵进行排序

例如

矩阵是我的myMat =
[1] [2]
[1，]苹果1
[2,1]香蕉3
[3，]梨4
[4，]黑莓5

索引字符串为
myIdx =
[1，]香蕉
[2,1]梨
[3，]苹果
[4，]黑莓

结果必须是
myResult =

[1] [2]
[1，]香蕉3
[2,1]梨4
[3，]苹果1
[4，]黑莓5

我怎么这样排序？感谢

Answer 1

使用data.table套餐，您可以轻松完成

myMat <- data.frame(fruit = c("apple", "banana", "pear", "blackberry"), num = c(1, 3, 4, 5))
myIdx <- c("banana", "pear", "apple", "blackberry")

require(data.table)
myMat <- data.table(myMat)
myMat
##         fruit num
## 1:      apple   1
## 2:     banana   3
## 3:       pear   4
## 4: blackberry   5

setkey(myMat, fruit)
myMat[J(myIdx)]

##         fruit num
## 1:     banana   3
## 2:       pear   4
## 3:      apple   1
## 4: blackberry   5