Returns the number of observations of a vector or data.frame. It uses
vctrs::vec_size() under the hood.
Arguments
- x
vector or data.frame
- names
logical; If TRUE the result is a named vector named "n_obs", else it is just the number of observations.
Note
You cannot use n_obs with features counting the key variable like
so - features(heights, country, n_obs). Instead, use any other variable.
Examples
n_obs(iris)
#> n_obs
#> 150
n_obs(1:10)
#> n_obs
#> 10
add_n_obs(heights)
#> # A tsibble: 1,490 x 5 [!]
#> # Key: country [144]
#> country year n_obs continent height_cm
#> <chr> <dbl> <int> <chr> <dbl>
#> 1 Afghanistan 1870 5 Asia 168.
#> 2 Afghanistan 1880 5 Asia 166.
#> 3 Afghanistan 1930 5 Asia 167.
#> 4 Afghanistan 1990 5 Asia 167.
#> 5 Afghanistan 2000 5 Asia 161.
#> 6 Albania 1880 4 Europe 170.
#> 7 Albania 1890 4 Europe 170.
#> 8 Albania 1900 4 Europe 169.
#> 9 Albania 2000 4 Europe 168.
#> 10 Algeria 1910 5 Africa 169.
#> # ℹ 1,480 more rows
heights %>%
features(height_cm, n_obs) # can be any variable except id, the key.
#> # A tibble: 144 × 2
#> country n_obs
#> <chr> <int>
#> 1 Afghanistan 5
#> 2 Albania 4
#> 3 Algeria 5
#> 4 Angola 9
#> 5 Argentina 20
#> 6 Armenia 11
#> 7 Australia 10
#> 8 Austria 18
#> 9 Azerbaijan 7
#> 10 Bahrain 3
#> # ℹ 134 more rows