How can I take the mean of each category and put it in a new dataframe?

Question

I'm trying to take the means of some data in terms of women and men and put it in a new dataframe. I can manage to do it for two columns using dplyr but, not for the whole dataframe. I used: df2 <- df1 %>% group_by(Genul) %>% summarise(average = mean(Apreciez că în condițiile actuale de pandemie, compania (Hotelul) în cadrul căreia sunt angajat a luat măsuri eficiente și suficiente de prevenție împotriva răspândirii virusului Sars-Cov-2 si contaminării cu acesta.)

The general syntax is `df2 % group_by(Genul) %>% summarise(across(c(col1, col2), mean, na.rm = TRUE))`. Replace `col1` and `col2` with your column names. — Ronak Shah, Mar 28 '21 at 07:03

score 1 · Answer 1 · answered Mar 28 '21 at 07:10

You can create your own summary function my_mean using {{}} and across

Then apply your function my_mean to the columns you want to calculate the mean

See below example with mtcars dataset:

library(dplyr)
my_mean <- function(data, col_names, na.rm = TRUE) {
  data %>% 
    summarise(across({{col_names}},
              list(mean = mean),
              na.rm = na.rm,
              .names = "{col}_{fn}"
    ))
}

mtcars %>% 
  group_by(cyl) %>% 
  my_mean(c(mpg, disp, hp, drat))

# Output:
# A tibble: 3 x 5
    cyl mpg_mean disp_mean hp_mean drat_mean
  <dbl>    <dbl>     <dbl>   <dbl>     <dbl>
1     4     26.7      105.    82.6      4.07
2     6     19.7      183.   122.       3.59
3     8     15.1      353.   209.       3.23

How can I take the mean of each category and put it in a new dataframe?

1 Answers1