如何导入字符列作为因子？

Question

我在 .txt 文件中有以下数据集：

1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,Action
0,0,0,2,0,0,0,2,0,0,0,0,0,0,0,0,Up
2,0,0,0,2,0,0,0,0,0,0,2,0,0,0,0,Left
4,0,0,2,0,0,0,0,0,2,0,0,0,0,0,0,Left
4,2,0,2,0,2,0,0,0,0,0,0,0,0,0,0,Up
4,4,0,0,2,0,0,0,0,0,0,0,0,0,0,2,Up
8,0,0,0,2,0,0,0,2,0,0,0,2,0,0,0,Left

当我将我的数据集加载到 RStudio 中时，我希望它将最后一列 Action 转换为 Factor 类型。但是，它认为它是 Character.

我可以强迫它把它当作因素，但它要求我

请插入逗号分隔的因素列表（您可以在下图中找到它）。但是，我不明白。我应该插入 Levels 的因子，还是将被整个 Action 列替换的值列表？

如何导入最后一列中带有 Factor 的数据集？

if 运行 str(dt) 它给了我：

Classes ‘tbl_df’, ‘tbl’ and 'data.frame':   2979 obs. of  17 variables:
 $ 1     : int  0 2 4 4 4 8 8 8 8 8 ...
 $ 2     : int  0 0 0 2 4 0 0 0 2 4 ...
 $ 3     : int  0 0 0 0 0 0 0 0 0 2 ...
 $ 4     : int  2 0 2 2 0 0 0 2 2 0 ...
 $ 5     : int  0 2 0 0 2 2 4 4 4 4 ...
 $ 6     : int  0 0 0 2 0 0 0 0 0 2 ...
 $ 7     : int  0 0 0 0 0 0 0 0 2 0 ...
 $ 8     : int  2 0 0 0 0 0 0 0 0 0 ...
 $ 9     : int  0 0 0 0 0 2 2 2 2 2 ...
 $ 10    : int  0 0 2 0 0 0 0 2 0 0 ...
 $ 11    : int  0 0 0 0 0 0 0 0 0 0 ...
 $ 12    : int  0 2 0 0 0 0 0 0 0 0 ...
 $ 13    : int  0 0 0 0 0 2 0 0 0 0 ...
 $ 14    : int  0 0 0 0 0 0 0 0 0 0 ...
 $ 15    : int  0 0 0 0 0 0 0 0 0 0 ...
 $ 16    : int  0 0 0 0 2 0 2 0 0 0 ...
 $ Action: chr  "Up" "Left" "Left" "Up" ...
 - attr(*, "spec")=List of 2
  ..$ cols   :List of 17
  .. ..$ 1     : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 2     : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 3     : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 4     : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 5     : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 6     : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 7     : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 8     : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 9     : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 10    : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 11    : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 12    : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 13    : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 14    : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 15    : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ 16    : list()
  .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
  .. ..$ Action: list()
  .. .. ..- attr(*, "class")= chr  "collector_character" "collector"
  ..$ default: list()
  .. ..- attr(*, "class")= chr  "collector_guess" "collector"
  ..- attr(*, "class")= chr "col_spec"

Answer 1

我们指定特定列的col_types或所有列

library(readr)
read_csv(file, col_type = cols(Action = col_factor(levels = c("Up", "Left"))))
# A tibble: 6 x 17
#    `1`   `2`   `3`   `4`   `5`   `6`   `7`   `8`   `9`  `10`  `11`  `12`  `13`  `14`  `15`  `16` Action
#  <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <fct> 
#1     0     0     0     2     0     0     0     2     0     0     0     0     0     0     0     0 Up    
#2     2     0     0     0     2     0     0     0     0     0     0     2     0     0     0     0 Left  
#3     4     0     0     2     0     0     0     0     0     2     0     0     0     0     0     0 Left  
#4     4     2     0     2     0     2     0     0     0     0     0     0     0     0     0     0 Up    
#5     4     4     0     0     2     0     0     0     0     0     0     0     0     0     0     2 Up    
#6     8     0     0     0     2     0     0     0     2     0     0     0     2     0     0     0 Left

Answer 2

使用基础 R，这也应该有效：read.table("FileName.txt", sep = ",", header = TRUE, stringsAsFactors = TRUE)

如何导入字符列作为因子？

How to import character column as factor?

r

rstudio

data-cleaning