r - 在列表中的多个列表中定义对象的名称(使用 lapply？)

Question

我为这个有点困惑的标题道歉(欢迎提出任何改进建议)..

假设我有一个包含多个(例如四个)列表的列表，稍后我想在其中存储 20 个对象:

mylist <- vector(mode="list",length=4)
names(mylist) <- c("One","Two","Three","Four")
mylist$One <- mylist$Two <- mylist$Three <- mylist$Four <- vector(mode="list",
                                                                  length=20)

我想预先定义那些对象的名称。当然，我可以这样做:

 names(mylist$One) <- c("A","B","C","D","E","F","G","H","I","J",
                        "K","L","M","N","O","P","Q","R","S","T")

 names(mylist$Two) <- names(mylist$Three) <- names(mylist$Four) <- names(mylist$One) 

但是如果列表的数量会增加(就像我的实际数据中的情况一样)，这会变得相当麻烦，所以我尝试使用 lapply 之类的函数来做到这一点:

mylist <- lapply(mylist,FUN=function(x) {names(x) <-   
                        c("A","B","C","D","E","F","G","H","I","J",
                          "K","L","M","N","O","P","Q","R","S","T")})

然而，这并没有给我相同的结果，但我似乎无法弄清楚我在这里忽略了什么。有什么建议么？

谢谢!

Answer 1

您需要在 lapply 调用中返回一个值:

mylist <- lapply(mylist,FUN=function(x) {names(x) <-   
                    c("A","B","C","D","E","F","G","H","I","J",
                      "K","L","M","N","O","P","Q","R","S","T")
                    x ## <- note the x here; you could also use return(x)
})

mylist
# $One
#   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T 
# "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S" "T" 
# 
# $Two
#   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T 
# "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S" "T" 
# 
# $Three
#   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T 
# "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S" "T" 
# 
# $Four
#   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T 
# "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S" "T"