Question

不确定tidyr::gather是否可用于获取多列并将其合并到多个键列中。

曾提出过类似的问题，但它们都涉及在一个关键列中收集多个列。

我正尝试将4列收集到2个键和2个值列中，如以下示例所示：

样本数据：

df <- data.frame(
    subject = c("a", "b"),
    age1 = c(33, 35),
    age2 = c(43, 45),
    weight1 = c(90, 67),
    weight2 = c(70, 87)
)

  subject age1 age2 weight1 weight2
1       a   33   43      90      70
2       b   35   45      67      87

所需结果：

dfe <- data.frame(
    subject = c("a", "a", "b", "b"),
    age = c("age1", "age2", "age1", "age2"),
    age_values = c(33, 43, 35, 45),
    weight = c("weight1", "weight2", "weight1", "weight2"),
    weight_values = c(90, 70, 67, 87)
)

  subject  age age_values  weight weight_values
1       a age1         33 weight1            90
2       a age2         43 weight2            70
3       b age1         35 weight1            67
4       b age2         45 weight2            87

Answer 1

这是一种方法。想法是先使用gather，然后按变量（年龄和体重）使用split得到的数据帧，对两个数据帧分别进行mutate操作，然后合并数据帧使用subject和变量号（1或2）一起返回。

library(dplyr)
library(tidyr)
library(purrr)

df %>%
  gather(age1:weight2, key = key, value = value) %>%
  separate(key, sep = -1, into = c("var", "num")) %>%
  split(.$var) %>%
  map(~mutate(., !!.$var[1] := paste0(var, num), !!paste0(.$var[1], "_values") := value)) %>%
  map(~select(., -var, -value)) %>%
  Reduce(f = merge, x = .) %>%
  select(-num)

Answer 2

这是一种方法-

df %>%
  gather(key = "age", value = "age_values", age1, age2) %>%
  gather(key = "weight", value = "weight_values", weight1, weight2) %>%
  filter(substring(age, 4) == substring(weight, 7))

  subject  age age_values  weight weight_values
1       a age1         33 weight1            90
2       b age1         35 weight1            67
3       a age2         43 weight2            70
4       b age2         45 weight2            87

r-使用tidyr在多个关键列中收集多个列

2 个答案: