如何修复使用 'nest' 导致列表列的列表？

Question

我正在使用包含一些信息的基础数据框，该信息用于生成一个新列，即数据框。

我尝试使用 map2 函数，但结果并不好，使用 nest 函数和包 purrr 中的 tibble 的结果更接近我的预期。

library(tidyverse)
library(dplyr)
library(purrr)
library(RcppRoll)

dfBase <- data.frame(id = sample(letters[1:3], 3, replace = TRUE),
              dat1 = rnorm(n = 3, 1, 1),
              dat2 = rnorm(n = 3, 2, 1))
View(dfBase)

dfOperations <- function(dat1, dat2){
Sum  = dat1+dat2
Rest = dat1-dat2
Mult = dat1*dat2
Div  = dat1/dat2

test <- tibble(
Opera = c('Sum','Rest','Mult','Div'),
Resul = c(Sum, Rest, Mult, Div))%>%nest()
} 

for (x in 1:nrow(dfBase)) {
dfBase$Result[x] <- dfOperations(dfBase$dat1[x],dfBase$dat2[x])
}


dfBase
str(dfBase)
View(dfBase$Result)

生成新列时，它会创建为列表列表而不是元素列表。

'data.frame':   3 obs. of  4 variables:
$ id    : Factor w/ 2 levels "b","c": 1 1 2
$ dat1  : num  0.53 1.29 1.19
$ dat2  : num  0.915 2.844 1.052
$ Result:List of 3
..$ :List of 1
 .. ..$ :Classes ‘tbl_df’, ‘tbl’ and 'data.frame':  4 obs. of  2 variables:
 .. .. ..$ Opera: chr  "Sum" "Rest" "Mult" "Div"
 .. .. ..$ Resul: num  1.444 -0.385 0.484 0.579
 ..$ :List of 1
 .. ..$ :Classes ‘tbl_df’, ‘tbl’ and 'data.frame':  4 obs. of  2 variables:
 .. .. ..$ Opera: chr  "Sum" "Rest" "Mult" "Div"
 .. .. ..$ Resul: num  4.136 -1.552 3.675 0.454
 ..$ :List of 1
 .. ..$ :Classes ‘tbl_df’, ‘tbl’ and 'data.frame':  4 obs. of  2 variables:
 .. .. ..$ Opera: chr  "Sum" "Rest" "Mult" "Div"
 .. .. ..$ Resul: num  2.246 0.143 1.256 1.136

如何删除或消除列表 1，只留下第二个列表 Opera 和 Resul？

Answer 1

尝试在每个循环迭代中使用 [[1]] 访问 dfOperations 的输出：

for (x in 1:nrow(dfBase)) {
dfBase$Result[x] <- dfOperations(dfBase$dat1[x],dfBase$dat2[x])[[1]]
}

'data.frame':   3 obs. of  4 variables:
 $ id    : Factor w/ 3 levels "a","b","c": 1 3 2
 $ dat1  : num  0.849 2.659 0.862
 $ dat2  : num  2.45 1.15 1.35
 $ Result:List of 3
  ..$ :Classes ‘tbl_df’, ‘tbl’ and 'data.frame':        4 obs. of  2 variables:
  .. ..$ Opera: chr  "Sum" "Rest" "Mult" "Div"
  .. ..$ Resul: num  3.301 -1.603 2.082 0.346
  ..$ :Classes ‘tbl_df’, ‘tbl’ and 'data.frame':        4 obs. of  2 variables:
  .. ..$ Opera: chr  "Sum" "Rest" "Mult" "Div"
  .. ..$ Resul: num  3.81 1.51 3.06 2.31
  ..$ :Classes ‘tbl_df’, ‘tbl’ and 'data.frame':        4 obs. of  2 variables:
  .. ..$ Opera: chr  "Sum" "Rest" "Mult" "Div"
  .. ..$ Resul: num  2.208 -0.484 1.16 0.64

如何修复使用 'nest' 导致列表列的列表？

How to fix the use of 'nest' to cause a list of list column?

r

dataframe

tibble