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!
最佳答案
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"
关于r - 在列表中的多个列表中定义对象的名称(使用 lapply?),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/18788613/