Correctly Applying Pivot Functions-CodePudding

I have this dataset:

my_data = structure(list(col = c("A", "B", "C"), `2000-01-01` = c(86L, 
43L, 73L), `2000-01-02` = c(99L, 77L, 12L)), class = "data.frame", row.names = c(NA, 
-3L))

  col 2000-01-01 2000-01-02
1   A         86         99
2   B         43         77
3   C         73         12

My goal is to transform this dataset into the following format:

        date col count
1 2000-01-01   A    86
2 2000-01-01   B    43
3 2000-01-01   C    73
4 2000-01-02   A    99
5 2000-01-02   B    77
6 2000-01-02   C    12

Have I done this correctly?

Here is my code:

library(tidyr)
# how come this seems to works for all columns even though I only specified "2001-01-01"?
my_data %>%
  pivot_longer(!col, names_to = "2001-01-01", values_to = "count")

# A tibble: 6 x 3
  col   `2001-01-01` count
  <chr> <chr>        <int>
1 A     2000-01-01      86
2 A     2000-01-02      99
3 B     2000-01-01      43
4 B     2000-01-02      77
5 C     2000-01-01      73
6 C     2000-01-02      12

Thanks!

CodePudding user response：

I would have done it like this:

library(tidyr)
library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union
structure(list(col = c("A", "B", "C"), `2000-01-01` = c(86L, 
                                                        43L, 73L), `2000-01-02` = c(99L, 77L, 12L)), class = "data.frame", row.names = c(NA, 
                                                                                                                                         -3L)
    ) %>% 
    pivot_longer(-col, names_to = 'date', values_to = 'count') %>% 
    arrange(date, col)
#> # A tibble: 6 × 3
#>   col   date       count
#>   <chr> <chr>      <int>
#> 1 A     2000-01-01    86
#> 2 B     2000-01-01    43
#> 3 C     2000-01-01    73
#> 4 A     2000-01-02    99
#> 5 B     2000-01-02    77
#> 6 C     2000-01-02    12

^{Created on 2022-12-09 with reprex v2.0.2}