将data.frame转换为列表列表 [英] Converting a data.frame to a list of lists

问题描述

如何转换data.frame

How can I convert a data.frame

df <- data.frame(id=c("af1", "af2"), start=c(100, 115), end=c(114,121))

列表列表

LoL <- list(list(id="af1", start=100, end=114), list(id="af2", start=115, end=121))

已经尝试过如

not.LoL <- as.list(as.data.frame(t(df)))

我真的不知道这是什么结果，但不是完全正确。我的要求是，我可以通过命令访问第一个开始

and I'm really not sure what I end up with after this, but it isn't quite right. My requirement is that I can access, say, the first start by the command

> LoL[[1]]$start
[1] 100

not.LoL ，我目前给了我以下错误：

the not.LoL that I currently have gives me the following error:

> not.LoL[[1]]$start
Error in not.LoL[[1]]$start : $ operator is invalid for atomic vectors

解释和/或解决方案将不胜感激。

Explanations and/or solutions would be greatly appreciated.

编辑：我应该明确表示id这里实际上是非唯一的 - 在单个ID下可以有多个元素。所以我可以使用不依赖于 split 的唯一ID的解决方案。

I should have made it clear that "id" here is actually non-unique - there can be multiple elements under a single ID. So I could do with a solution that doesn't depend on unique IDs to split on.

推荐答案

使用 plyr 可以这样做

dlply(df,.(id),c)

为了避免按ID分组，如果有（或许你需要更改列名，id对我来说是唯一的）

To avoid grouping by id , if there are multiple ( maybe you need to change column name , id is unique for me)

dlply(df,1,c)

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