How can I reorder facet wrap by the values of the first column?

Question

The following code is from Stefan, who answered a related question

library(ggplot2)
library(dplyr)
library(tidyr)
library(tidytext)

mtcars2 <- as_tibble(mtcars, rownames = 'car')

mtcars_long_numeric_with_mpg <- mtcars2 %>%
  select(car, mpg, disp, hp, drat, wt, qsec) %>% 
  pivot_longer(names_to = 'names', values_to = 'values', 2:7) %>% 
  mutate(car = tidytext::reorder_within(car, values, names))

ggplot(mtcars_long_numeric_with_mpg, aes(x = values, y = reorder(car, values))) +
  geom_point() + 
  tidytext::scale_y_reordered() +
  facet_wrap(~names, scales = 'free')+
  theme(text = element_text(size=6))

What I'm wondering is how to reorder each plot by the values of the first plot. So if I wanted each subsequent plot to be ordered by the values from greatest to largest (or vice versa) of the 'disp' values, rather than each ordered by its own sorted values. I know I have to fix the y-axis, which I have already done, but I can't figure out how to sort all values by just the first facet. Thanks in advance for any help!

Answer 1

you could reorder car by disp before melting the dataframe to long format:

mtcars_long <-
    mtcars %>% 
    rownames_to_column('car') %>%
    ## set the levels of factor 'model' before reshaping:
    mutate(model = fct_reorder(model, disp, mean)) %>%
    pivot_longer(cols = -car, ## stack all columns except 'car'
                 names_to = 'parameter'
                 ) ## stack all columns except model