将R中的文本数据从列透视到行

# 宽格式数据
df <- data.frame(
  id = 1:3,
  time1 = c(10, 20, 30),
  time2 = c(15, 25, 35),
  time3 = c(20, 30, 40)
)

# 使用pivot_longer()函数将数据从列透视到行
library(tidyr)

df_long <- df %>%
  pivot_longer(
    cols = starts_with("time"),
    names_to = "time_point",
    values_to = "value"
  )

print(df_long)

# A tibble: 9 x 3
     id time_point value
  <int> <chr>      <dbl>
1     1 time1         10
2     1 time2         15
3     1 time3         20
4     2 time1         20
5     2 time2         25
6     2 time3         30
7     3 time1         30
8     3 time2         35
9     3 time3         40

df_long <- df %>%
  pivot_longer(
    cols = matches("time\\d+"),
    names_to = "time_point",
    values_to = "value"
  )

df_long <- df %>%
  pivot_longer(
    cols = starts_with("time"),
    names_to = "time_point",
    values_to = "value",
    na.rm = TRUE
  )