如何在 R 中将宽嵌套数据重塑为长格式?

How do I reshape wide nested data to long format in R?

我有一个看起来像这样的数据集,每个教室 (ID) 有不同的团队 (A, B),每个团队有 3 个分数(例如,team1_1 team1_2 team1_3) 和每队的平均分。也就是说,1号教室有两队(A,B),2号教室有两队(A,B),以此类推。

df <- data.frame(ID=1:5,
                 Team1=c("A","A","A","A","A"),
                 Team1_1=c(2,3,1,3,4),
                 Team1_2=c(4,2,2,3,2),
                 Team1_3=c(5,3,4,5,4),
                 Team1_Mean=c(3.67,2.67,2.33,3.67,3.33),
                 Team2=c("B","B","B","B","B"),
                 Team2_1=c(4,3,3,5,4),
                 Team2_2=c(4,2,2,5,2),
                 Team2_3=c(4,4,4,5,3),
                 Team2_Mean=c(4,3,3,5,3))


ID Team1 Team1_1 Team1_2 Team1_3 Team1_Mean Team2 Team2_1 Team2_2 Team2_3 Team2_Mean
1    A      2       4       5      3.67       B      4       4       4         4
2    A      3       2       3      2.67       B      3       2       4         3
3    A      1       2       4      2.33       B      3       2       4         3
4    A      3       3       5      3.67       B      5       5       5         5
5    A      4       2       4      3.33       B      4       2       3         3

我想重塑数据,以便每个团队都以长格式列出,如下所示:

df2 <- data.frame(ID=c(1,1,2,2,3,3,4,4,5,5),
                  Team=c("A", "B", "A", "B", "A", "B", "A", "B", "A", "B"),
                  Score1=c(2,4,3,3,1,3,3,5,4,5),
                  Score2=c(4,4,2,2,2,2,3,5,2,2),
                  Score3=c(5,4,3,4,4,4,5,5,4,3),
                  Mean=c(3.67,4,2.67,3,2.33,3,3.67,5,3.33,3))


ID Team Score1 Score2 Score3 Mean
1   A     2      4      5    3.67
1   B     4      4      4    4.00
2   A     3      2      3    2.67
2   B     3      2      4    3.00
3   A     1      2      4    2.33
3   B     3      2      4    3.00
4   A     3      3      5    3.67
4   B     5      5      5    5.00
5   A     4      2      4    3.33
5   B     5      2      3    3.00

在我看来,我认为将每个团队的数据放在一个列表中,重新整形为长格式,然后取消嵌套数据就可以解决问题,但这并不容易。我的第一步是这样的:

df <- df %>% nest(items = c("Team1", "Team1_1", "Team1_2", "Team1_3", "Team1_Mean"))
names(df)[names(df) == "items"] <- "Team1"
df <- df %>% nest(items = c("Team2", "Team2_1", "Team2_2", "Team2_3", "Team2_Mean"))
names(df)[names(df) == "items"] <- "Team2"


# A tibble: 5 x 3
     ID Team1            Team2           
  <int> <list>           <list>          
1     1 <tibble [1 × 5]> <tibble [1 × 5]>
2     2 <tibble [1 × 5]> <tibble [1 × 5]>
3     3 <tibble [1 × 5]> <tibble [1 × 5]>
4     4 <tibble [1 × 5]> <tibble [1 × 5]>
5     5 <tibble [1 × 5]> <tibble [1 × 5]>

从那里我尝试了我常用的 reshape2(熔化)函数,但 R 说它已被弃用,所以我尝试了 tidyr 的“收集”方法,但这些努力似乎不适用于列表。

我的问题是:

  1. 如何实现我想要的结果?
  2. 我的数据集包含数百个 ID 和团队,所以我不想像上面那样输入每个变量;我怎样才能简化它以减少硬编码的使用?

非常感谢!

一个选项是pivot_longer。我们可以 rename 列 'Team1'、'Team2' 添加分隔符 (_) 以及后缀 'Team',然后重塑为 'long' 格式pivot_longer 指定 cols 除了 'ID' (-ID),指定 names_sep_ 然后 rename以数字开头并附加 'Score' 作为前缀

的列名
library(dplyr)
library(tidyr)
library(stringr)
df %>%
   rename_at(vars(matches("^Team\d+$")), ~ str_c(., "_Team")) %>%  
   pivot_longer(cols = -ID, names_to = c("grp", ".value"), 
            names_sep="_")%>% 
   rename_at(vars(matches('^\d+')), ~ str_c("Score", .)) %>%
   select(-grp)

-输出

# A tibble: 10 x 6
#      ID Team  Score1 Score2 Score3  Mean
#   <int> <chr>  <dbl>  <dbl>  <dbl> <dbl>
# 1     1 A          2      4      5  3.67
# 2     1 B          4      4      4  4   
# 3     2 A          3      2      3  2.67
# 4     2 B          3      2      4  3   
# 5     3 A          1      2      4  2.33
# 6     3 B          3      2      4  3   
# 7     4 A          3      3      5  3.67
# 8     4 B          5      5      5  5   
# 9     5 A          4      2      4  3.33
#10     5 B          4      2      3  3   

这是使用 stack + gsub + unstack

的基础 R 选项
q <- unstack(
  transform(
    stack(df),
    ind = gsub("(?<=Team)\d+", "", ind, perl = TRUE)
  )
)
q$ID <- rep(q$ID, max(lengths(q)) / length(q$ID))
q <- type.convert(q, as.is = TRUE)
dfout <- data.frame(q)[order(q$ID), ]

这给出了

> dfout
   ID Team Team_1 Team_2 Team_3 Team_Mean
1   1    A      2      4      5      3.67
6   1    B      4      4      4      4.00
2   2    A      3      2      3      2.67
7   2    B      3      2      4      3.00
3   3    A      1      2      4      2.33
8   3    B      3      2      4      3.00
4   4    A      3      3      5      3.67
9   4    B      5      5      5      5.00
5   5    A      4      2      4      3.33
10  5    B      4      2      3      3.00

您可以使用 melt from data.table and pass a list of patterns,以及新的列名:

result <- melt(setDT(df), id=c("ID"), measure = patterns(Team = "Team\d$", 
                                                Score1 = "Team\d_1$", 
                                                Score2 = "Team\d_2$", 
                                                Score3 = "Team\d_3$", 
                                                Mean = ".+Mean$"))

result[order(ID), !c("variable")] 

    ID Team Score1 Score2 Score3 Mean
 1:  1    A      2      4      5 3.67
 2:  1    B      4      4      4 4.00
 3:  2    A      3      2      3 2.67
 4:  2    B      3      2      4 3.00
 5:  3    A      1      2      4 2.33
 6:  3    B      3      2      4 3.00
 7:  4    A      3      3      5 3.67
 8:  4    B      5      5      5 5.00
 9:  5    A      4      2      4 3.33
10:  5    B      4      2      3 3.00