r - R如何根据现有数据创建列/功能

Question

我有一个数据框df:

userID Score  Task_Alpha Task_Beta Task_Charlie Task_Delta 
3108  -8.00   Easy       Easy      Easy         Easy    
3207   3.00   Hard       Easy      Match        Match
3350   5.78   Hard       Easy      Hard         Hard
3961   10.00  Easy       NA        Hard         Hard
4021   10.00  Easy       Easy      NA           Hard


1. userID is factor variable
2. Score is numeric
3. All the 'Task_' features are factor variables with possible values 'Hard', 'Easy', 'Match' or NA

我想为每个 userID创建新列，其中包含 Task_功能的每种可能状态的出现次数。对于上面的玩具示例，所需的输出将是在 df的末尾追加的三个新列，如下所示:

userID Hard Match Easy
3108   0    0     4
3207   1    2     1
3350   3    0     1
3961   2    0     1
4021   1    0     2

更新:
该问题不是重复的问题，原始问题的相关部分已移至:
R How to counting the factors in ordered sequence

Answer 1

您可以将数据帧df与map*或*apply函数中的每个值进行比较，计算所得 bool 矩阵的行和，然后将输出与原始数据帧组合:

library(dplyr)
library(purrr)

facs <- c("Easy", "Match", "Hard")

bind_cols(df, set_names(map_dfc(facs, ~ rowSums(df == ., na.rm = T)), facs))

#### OUTPUT ####

  userID Score Task_Alpha Task_Beta Task_Charlie Task_Delta Easy Match Hard
1   3108 -8.00       Easy      Easy         Easy       Easy    4     0    0
2   3207  3.00       Hard      Easy        Match      Match    1     2    1
3   3350  5.78       Hard      Easy         Hard       Hard    1     0    3
4   3961 10.00       Easy      <NA>         Hard       Hard    1     0    2
5   4021 10.00       Easy      Easy         <NA>       Hard    2     0    1