Dplyr :: summaryize_at - sort columns in order of passed variables, then in order of applied functions

Question

Problem

Using dplyr::summarize_at()(or equivalent), I would like to get a summary table in which the columns are first sorted by the order of grouping of variables (G) , and then by (V) , and finally, the applied order of functions (F) . The default order is determined first by G, then F, and finally V.

Example

The code:

library(purrr)
library(dplyr)

q025 <- partial(quantile, probs  = 0.025, na.rm = TRUE)
q975 <- partial(quantile, probs  = 0.975, na.rm = TRUE)

vars_to_summarize <- c("height", "mass")

my_summary <- starwars %>% 
    filter(skin_color  %in% c("gold", "green")) %>% 
    group_by(skin_color) %>% 
    summarise_at(vars_to_summarize, funs(q025, mean, q975))

Results in:

my_summary
## A tibble: 2 x 7
##   skin_color height_q025 mass_q025 height_mean mass_mean height_q975 mass_q975
##        <chr>       <dbl>     <dbl>       <dbl>     <dbl>       <dbl>     <dbl>
## 1       gold     167.000      75.0         167        75      167.00      75.0
## 2      green      79.375      22.7         169        NA      204.75     110.4

And the desired order of variables should be:

skin_color, height_q025, height_mean, height_q975, mass_q025, mass_mean, mass_q975

I would like to use something like this (naively simple) code:

my_summary  %>% 
    select(everything(), starts_with(vars_to_summarize))

But that will not work. Even this code does not work as I expect (although this is not the general solution I'm looking for):

my_summary  %>% 
    select(everything(),
           starts_with(vars_to_summarize[1]),
           starts_with(vars_to_summarize[2]))

Most likely, everything()should always be the last argument in select().

, :

• N ( "gr_" ), group_by(),
• L ( "var_" ),
• M ( "fun _" ).

:

gr_1, gr_2, ..., gr_N,   
var_1_fun_1, var_1_fun_2, ..., var_1_fun_M,  
var_2_fun_1, var_2_fun_2, ..., var_2_fun_M, 
...,
var_L_fun_1, var_L_fun_2, ..., var_L_fun_M

Answer 1

matches grep

my_summary %>%
    select(grep(paste(vars_to_summarize, collapse="|"), names(.), invert = TRUE), 
           matches(vars_to_summarize[1]),
           matches(vars_to_summarize[2]))
# A tibble: 2 x 7
#    skin_color height_q025 height_mean height_q975 mass_q025 mass_mean mass_q975
#       <chr>       <dbl>       <dbl>       <dbl>     <dbl>     <dbl>     <dbl>
#1       gold     167.000         167      167.00      75.0        75      75.0
#2      green      79.375         169      204.75      22.7        NA     110.4

---

, _ , match 'vars_to_summarize' order select

my_summary %>% 
   select(order(match(sub("_.*", "", names(.)), vars_to_summarize, nomatch = 0)))
# A tibble: 2 x 7
#    skin_color height_q025 height_mean height_q975 mass_q025 mass_mean mass_q975
#       <chr>       <dbl>       <dbl>       <dbl>     <dbl>     <dbl>     <dbl>
#1       gold     167.000         167      167.00      75.0        75      75.0
#2      green      79.375         169      204.75      22.7        NA     110.4