将数据从宽变长：基于列名的新变量

Question

我想将数据集从宽格式重塑为长格式。

数据集包含 300 个变量，每个变量都以原理命名：ModelID_Emotion_ModelGender。以下示例数据：

df <- structure(list(X71_Anger_Male = structure(c(3L, 1L, 2L), .Label = c("Anger", 
"Disgust", "Fear"), class = "factor"), X71_Disgus_Male = structure(c(2L, 
1L, 1L), .Label = c("Disgust", "Fear"), class = "factor")), class = "data.frame", row.names = c(NA, 
-3L))

看起来像

  X71_Anger_Male X71_Disgus_Male
1           Fear            Fear
2          Anger         Disgust
3        Disgust         Disgust

我想以将列名中的信息获取并放入新变量的方式转置数据。例如，应该有一个新变量ModelGender，一个新变量modelID和一个新变量emotion。所以数据集应该是这样的：

desired <- structure(list(Gender = structure(c(1L, 1L, 1L, 1L, 1L, 1L), .Label = "Male", class = "factor"), 
    ModelNumber = structure(c(1L, 1L, 1L, 1L, 1L, 1L), .Label = "X71", class = "factor"), 
    Emotion = structure(c(2L, 2L, 2L, 1L, 1L, 1L), .Label = c("Anger", 
    "Disgust"), class = "factor"), Response = structure(c(3L, 
    2L, 2L, 3L, 1L, 2L), .Label = c("Anger", "Disgust", "Fear"
    ), class = "factor")), class = "data.frame", row.names = c(NA, 
-6L))

应该是这样的

  Gender ModelNumber Emotion Response
1   Male         X71 Disgust     Fear
2   Male         X71 Disgust  Disgust
3   Male         X71 Disgust  Disgust
4   Male         X71   Anger     Fear
5   Male         X71   Anger    Anger
6   Male         X71   Anger  Disgust

当我使用 reshape、gather/spread 或 melt/cast 时，它不会给出预期的结果。有没有人知道如何做到这一点？

感谢您的宝贵时间！

Answer 1

您可以简单地转换为 long 并拆分您想要的列。一种通过 tidyverse 方法的方法可以是，

library(dplyr)
library(tidyr)

df %>% 
 pivot_longer(everything()) %>% 
 separate(name, into = c('ModelNumber', 'Emotion', 'Gender'), sep = '_')

Answer 2

在pivot_longer 中，您可以将names_sep 指定为"_" 并将列名拆分为3 列。

tidyr::pivot_longer(df, cols = everything(),
                        names_to = c('ModelNumber', 'Emotion', 'Gender'), 
                        values_to = 'Response',
                        names_sep = '_')

# A tibble: 6 x 4
#  ModelNumber Emotion Gender Response
#  <chr>       <chr>   <chr>  <fct>   
#1 X71         Anger   Male   Fear    
#2 X71         Disgus  Male   Fear    
#3 X71         Anger   Male   Anger   
#4 X71         Disgus  Male   Disgust 
#5 X71         Anger   Male   Disgust 
#6 X71         Disgus  Male   Disgust