将数据框转换为列表 [英] Convert data frame to list

问题描述

我正在尝试从数据框到 R 中的列表结构(我知道从技术上讲数据框是一个列表).我有一个包含参考化学品及其机制不同目标的数据框.例如，雌激素是一种雌激素受体激动剂.我想要的是将数据框转换为列表，因为我厌倦了键入以下内容:

I am trying to go from a data frame to a list structure in R (and I know technically a data frame is a list). I have a data frame containing reference chemicals and their mechanisms different targets. For example, estrogen is an estrogen receptor agonist. What I would like is to transform the data frame to a list, because I am tired of typing out something like:

refchem$chemical_id[refchem$target=="AR" & refchem$mechanism=="Agonist"]

每次我需要访问特定参考化学品的列表时.我更愿意通过以下方式获取化学品:

every time I need to access the list of specific reference chemicals. I would much rather access the chemicals by:

refchem$AR$Agonist

我正在寻找一个通用的答案，尽管我给出了一个简化的例子，因为并非所有的目标都有所有的机制.

I am looking for a general answer, even though I have given a simplified example, because not all targets have all mechanisms.

这很容易用循环来完成:

This is really easy to accomplish with a loop:

example <- data.frame(target=rep(c("t1","t2","t3"),each=20),
                      mechan=rep(c("m1","m2"),each=10,3),
                      chems=paste0("chem",1:60))
oneoption <- list()
for(target in unique(example$target)){
  oneoption[[target]] <- list()
  for(mech in unique(example$mechan)){
    oneoption[[target]][[mech]] <- as.character(example$chems[ example$target==target & example$mechan==mech ])
  }
}

我只是想知道是否有更聪明的方法来做到这一点.我尝试使用 lapply 并没有取得任何进展.

I am just wondering if there is a more clever way to do it. I tried playing around with lapply and did not make any progress.

推荐答案

使用split:

split(refchem, list(refchem$target, refchem$mechanism))

应该可以.

新的访问方式是 refchem$AR.Agonist

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