tentidy7.R

penguin_stats <- penguins %>% 
  dplyr::group_by(species) %>% 
  dplyr::summarise(across(ends_with("mm"), 
                          list(mean = ~mean(.x, na.rm = TRUE), sd = ~sd(.x, na.rm = TRUE)), # name summary functions
                          .names = "{gsub('_|_mm', '', col)}_{fn}")) # structure for summarised column names

penguin_stats

# A tibble: 3 x 7
  species   billlength_mean billlength_sd billdepth_mean billdepth_sd flipperlength_mean flipperlength_sd
  <fct>               <dbl>         <dbl>          <dbl>        <dbl>              <dbl>            <dbl>
1 Adelie               38.8          2.66           18.3        1.22                190.             6.54
2 Chinstrap            48.8          3.34           18.4        1.14                196.             7.13
3 Gentoo               47.5          3.08           15.0        0.981               217.             6.48