有关add add_row和group_by的问题.在add_row中需要group_by变量名

Question

问题:我想使用dplyr/tibble添加add_row.我想在我的示例中按A分组数据,然后是包含组名A的add_row,然后是B的值.

我面临的问题是尝试在A下的列中添加Group_by变量A.无论我尝试什么,它总是返回错误或NA作为该列中的值.

1. 可重复的例子:

   example <- data.frame(A = sample(letters[1:3],10,replace = TRUE), 
                 B = sample(letters[24:26],10,replace = TRUE),
                 C = sample(1:3,10,replace = TRUE))
   

2. 示例数据的输出:

         A B C
      1  c y 2
      2  b x 3
      3  c y 1
      4  b y 1
      5  c z 1
      6  a x 1
      7  b x 1
      8  c z 2
      9  a y 3
      10 c y 1
   

3. 代码我想运行.

   answer <- example %>%
     mutate(A = as.character(A),
            B = as.character(B)) %>%
     group_by(A) %>%
     do(add_row(., 
                B = "ADDED",
                C = "ADDED"))
   

4. 输出数据:

           A     B     C
     1     a     x     1
     2     a     y     3
     3  <NA> ADDED ADDED
     4     b     x     3
     5     b     y     1
     6     b     x     1
     7  <NA> ADDED ADDED
     8     c     y     2
     9     c     y     1
    10     c     z     1
    11     c     z     2
    12     c     y     1
    13  <NA> ADDED ADDED
   

5. 所以在数据的输出中,如果有NA,我希望它说组名(a,b或c)

我试过在那里只放置组变量名称,它不起作用会引发错误.

谢谢!

Answer 1

你可以直接在里面添加它do.

example %>%
    mutate_if(is.factor, as.character) %>%
    group_by(A) %>%
    do(add_row(., 
               A = unique(.$A),
               B = "ADDED",
               C = "ADDED"))

或者tidyr::fill在最后使用.因为它必须ungroup首先填充分组变量.

library(tidyr)

example %>%
    mutate_if(is.factor, as.character) %>%
    group_by(A) %>%
    do(add_row(.,
               B = "ADDED",
               C = "ADDED")) %>%
    ungroup() %>%
    fill(A)

# A tibble: 13 x 3
       A     B     C
   <chr> <chr> <chr>
 1     a     z     2
 2     a     x     1
 3     a     y     2
 4     a ADDED ADDED
 5     b     y     1
 6     b     z     1
 7     b ADDED ADDED
 8     c     z     2
 9     c     y     2
10     c     z     2
11     c     y     2
12     c     z     1
13     c ADDED ADDED