tentidy6.R

penguin_stats <- penguins %>% 
  dplyr::group_by(species) %>% 
  dplyr::summarise(across(ends_with("mm"), # do this for any column ending in mm
                          list(~mean(.x, na.rm = TRUE), ~sd(.x, na.rm = TRUE)))) # calculate a mean and sd

penguin_stats

# A tibble: 3 x 7
  species   bill_length_mm_1 bill_length_mm_2 bill_depth_mm_1 bill_depth_mm_2 flipper_length_mm_1 flipper_length_mm_2
  <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