Return the number of observations

Returns the number of observations of a vector or data.frame. It uses vctrs::vec_size() under the hood.

n_obs(x, names = TRUE)

Arguments

x	vector or dataframe
names	logical; If TRUE the result is a named vector named "n_obs", else it is just the number of observations.

Value

number of observations

Note

You cannot use n_obs with features counting the key variable like so - features(wages, id, n_obs). Instead, use any other variable.

Examples

n_obs(iris)
#> n_obs 
#>   150 
n_obs(1:10)
#> n_obs 
#>    10 
add_n_obs(wages)
#> # A tsibble: 6,402 x 10 [!]
#> # Key:       id [888]
#>       id    xp n_obs ln_wages   ged xp_since_ged black hispanic high_grade
#>    <int> <dbl> <int>    <dbl> <int>        <dbl> <int>    <int>      <int>
#>  1    31 0.015     8     1.49     1        0.015     0        1          8
#>  2    31 0.715     8     1.43     1        0.715     0        1          8
#>  3    31 1.73      8     1.47     1        1.73      0        1          8
#>  4    31 2.77      8     1.75     1        2.77      0        1          8
#>  5    31 3.93      8     1.93     1        3.93      0        1          8
#>  6    31 4.95      8     1.71     1        4.95      0        1          8
#>  7    31 5.96      8     2.09     1        5.96      0        1          8
#>  8    31 6.98      8     2.13     1        6.98      0        1          8
#>  9    36 0.315    10     1.98     1        0.315     0        0          9
#> 10    36 0.983    10     1.80     1        0.983     0        0          9
#> # … with 6,392 more rows, and 1 more variable: unemploy_rate <dbl>
wages %>%
  features(ln_wages, n_obs) # can be any variable except id, the key.
#> # A tibble: 888 x 2
#>       id n_obs
#>    <int> <int>
#>  1    31     8
#>  2    36    10
#>  3    53     8
#>  4   122    10
#>  5   134    12
#>  6   145     9
#>  7   155    11
#>  8   173     6
#>  9   206     3
#> 10   207    11
#> # … with 878 more rows