通过将现有行的一部分移动到新行来重塑数据帧

Question

我的数据格式为：

structure(list(choice = structure(c(1L, 1L, 2L, 1L), .Label = c("option1", 
"option2"), class = "factor"), option1var1 = structure(c(1L, 
1L, 1L, 1L), .Label = "A", class = "factor"), option1var2 = structure(c(1L, 
1L, 1L, 2L), .Label = c("B", "H"), class = "factor"), option2var1 = structure(c(1L, 
1L, 2L, 3L), .Label = c("C", "F", "I"), class = "factor"), option2var2 = structure(1:4, .Label = c("D", 
"E", "G", "K"), class = "factor")), .Names = c("choice", "option1var1", 
"option1var2", "option2var1", "option2var2"), class = "data.frame", row.names = c(NA, 
-4L))

有六列。第一列包含响应者ID，第二列包含有关响应者选择的数据（option1或option2），第3列和第4列包含与option1关联的属性，第4列和第5列包含与option2关联的属性。

我想转换数据框，使其看起来像这样：

structure(list(respondent = c(1L, 1L, 2L, 2L, 3L, 3L, 4L, 4L), 
    choice = c(1L, 0L, 1L, 0L, 0L, 1L, 1L, 0L), option = structure(c(1L, 
    2L, 1L, 2L, 1L, 2L, 1L, 2L), .Label = c("option1", "option2"
    ), class = "factor"), var1 = structure(c(1L, 2L, 1L, 2L, 
    1L, 3L, 1L, 4L), .Label = c("A", "C", "F", "I"), class = "factor"), 
    var2 = structure(c(1L, 2L, 1L, 3L, 1L, 4L, 5L, 6L), .Label = c("B", 
    "D", "E", "G", "H", "K"), class = "factor")), .Names = c("respondent", 
"choice", "option", "var1", "var2"), class = "data.frame", row.names = c(NA, 
-8L))

这需要将每一行拆分为两行，将option1数据保留在一行中，并将option2数据移动到另一行，以及创建一个新的数字变量，其中包含有关哪个选项的信息（每个响应者选择选项1或选项2）。

似乎没有关于此类转换的任何信息 - 无论是在这里还是在我发现的R文档中。有谁知道怎么做？

Answer 1

假设原始数据框为df1，最终输出为df2。

library(tidyverse)

df2 <- df1 %>%
  mutate(respondent = 1:n()) %>%
  gather(Option, Value, starts_with("option")) %>%
  separate(Option, into = c("option", "Var"), sep = 7) %>%
  mutate(choice = ifelse(choice == option, 1L, 0L)) %>%
  spread(Var, Value) %>%
  select(respondent, choice, option, starts_with("var")) %>%
  arrange(respondent, option)
df2
#   respondent choice  option var1 var2
# 1          1      1 option1    A    B
# 2          1      0 option2    C    D
# 3          2      1 option1    A    B
# 4          2      0 option2    C    E
# 5          3      0 option1    A    B
# 6          3      1 option2    F    G
# 7          4      1 option1    A    H
# 8          4      0 option2    I    K