在 R 中的 for 循环中将元素添加到列表中 [英] Adding elements to a list in for loop in R

问题描述

我正在尝试在 for 循环中将元素添加到列表中.如何设置字段名称?

I'm trying to add elements to a list in a for loop. How can I set the field name?

L<-list() 
    for(i in 1:N)
    {
        #Create object Ps...
        string<-paste("element",i,sep="")
        L$get(string)<-Ps
    }

我希望列表中的每个元素都具有依赖于 i 的字段名称(例如，第二个元素应该具有element2")

I want every element of the list to have the field name dependent from i (for example, the second element should have "element2")

如何做到这一点?我认为我的错误是 get

How to do this? I think that my error is the usage of get

推荐答案

您似乎正在寻找如下所示的结构:

It seems like you're looking for a construct like the following:

N <- 3
x <- list()
for(i in 1:N) {
    Ps <- i  ## where i is whatever your Ps is
    x[[paste0("element", i)]] <- Ps
}
x
# $element1
# [1] 1
#
# $element2
# [1] 2
#
# $element3
# [1] 3

虽然，如果你事先知道N，那么分配x然后填充它而不是添加到现有列表是更好的实践和更有效的做法.>

Although, if you know N beforehand, then it is better practice and more efficient to allocate x and then fill it rather than adding to the existing list.

N <- 3
x <- vector("list", N)
for(i in 1:N) {
    Ps <- i  ## where i is whatever your Ps is
    x[[i]] <- Ps
}
setNames(x, paste0("element", 1:N))
# $element1
# [1] 1
#
# $element2
# [1] 2
#
# $element3
# [1] 3

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