Intermezzo: missing values (1)

billboard
## # A tibble: 317 × 79
##    artist     track date.entered   wk1   wk2   wk3   wk4   wk5   wk6   wk7   wk8
##    <chr>      <chr> <date>       <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
##  1 2 Pac      Baby… 2000-02-26      87    82    72    77    87    94    99    NA
##  2 2Ge+her    The … 2000-09-02      91    87    92    NA    NA    NA    NA    NA
##  3 3 Doors D… Kryp… 2000-04-08      81    70    68    67    66    57    54    53
##  4 3 Doors D… Loser 2000-10-21      76    76    72    69    67    65    55    59
##  5 504 Boyz   Wobb… 2000-04-15      57    34    25    17    17    31    36    49
##  6 98^0       Give… 2000-08-19      51    39    34    26    26    19     2     2
##  7 A*Teens    Danc… 2000-07-08      97    97    96    95   100    NA    NA    NA
##  8 Aaliyah    I Do… 2000-01-29      84    62    51    41    38    35    35    38
##  9 Aaliyah    Try … 2000-03-18      59    53    38    28    21    18    16    14
## 10 Adams, Yo… Open… 2000-08-26      76    76    74    69    68    67    61    58
## # ℹ 307 more rows
## # ℹ 68 more variables: wk9 <dbl>, wk10 <dbl>, wk11 <dbl>, wk12 <dbl>,
## #   wk13 <dbl>, wk14 <dbl>, wk15 <dbl>, wk16 <dbl>, wk17 <dbl>, wk18 <dbl>,
## #   wk19 <dbl>, wk20 <dbl>, wk21 <dbl>, wk22 <dbl>, wk23 <dbl>, wk24 <dbl>,
## #   wk25 <dbl>, wk26 <dbl>, wk27 <dbl>, wk28 <dbl>, wk29 <dbl>, wk30 <dbl>,
## #   wk31 <dbl>, wk32 <dbl>, wk33 <dbl>, wk34 <dbl>, wk35 <dbl>, wk36 <dbl>,
## #   wk37 <dbl>, wk38 <dbl>, wk39 <dbl>, wk40 <dbl>, wk41 <dbl>, wk42 <dbl>, …
billboard %>% 
  pivot_longer(
    cols = starts_with("wk"), 
    names_to = "week", 
    values_to = "rank"
  )
## # A tibble: 24,092 × 5
##    artist track                   date.entered week   rank
##    <chr>  <chr>                   <date>       <chr> <dbl>
##  1 2 Pac  Baby Don't Cry (Keep... 2000-02-26   wk1      87
##  2 2 Pac  Baby Don't Cry (Keep... 2000-02-26   wk2      82
##  3 2 Pac  Baby Don't Cry (Keep... 2000-02-26   wk3      72
##  4 2 Pac  Baby Don't Cry (Keep... 2000-02-26   wk4      77
##  5 2 Pac  Baby Don't Cry (Keep... 2000-02-26   wk5      87
##  6 2 Pac  Baby Don't Cry (Keep... 2000-02-26   wk6      94
##  7 2 Pac  Baby Don't Cry (Keep... 2000-02-26   wk7      99
##  8 2 Pac  Baby Don't Cry (Keep... 2000-02-26   wk8      NA
##  9 2 Pac  Baby Don't Cry (Keep... 2000-02-26   wk9      NA
## 10 2 Pac  Baby Don't Cry (Keep... 2000-02-26   wk10     NA
## # ℹ 24,082 more rows