宽表变长表 - 图1

    1. ## Example 1:
    2. stocks = data.frame(
    3.   time = as.Date('2009-01-01') + 0:9,
    4.   X = rnorm(10, 0, 1),
    5.   Y = rnorm(10, 0, 2),
    6.   Z = rnorm(10, 0, 4)
    7. )
    8. stocks
    10. stocks %>%
    11.   longer_dt(time)
    13. stocks %>%
    14.   longer_dt("ti")
    17. # Example 2:
    18. library(tidyr)
    20. billboard %>%
    21.   longer_dt(
    22.     -"wk",
    23.     name = "week",
    24.     value = "rank",
    25.     na.rm = TRUE
    26.   )
    27. # or use:
    28. billboard %>%
    29.   longer_dt(
    30.     artist,track,date.entered,
    31.     name = "week",
    32.     value = "rank",
    33.     na.rm = TRUE
    34.   )
    35. # or use:
    36. billboard %>%
    37.   longer_dt(
    38.     1:3,
    39.     name = "week",
    40.     value = "rank",
    41.     na.rm = TRUE
    42.   )