I am trying to add a totals row usin ghte Janitor package in R, however I need 2 columns to be totaled using the sum function and one column to be a percentage (not the sum of the column).

library(tidyverse)
library(janitor)

df.1 <- tribble(
~customer  ,~period, ~cost1, ~cost2 ,
'cust1',  '202201', 5, 10,
'cust1',  '202202', 5, 10,
'cust1',  '202203', 5, 10,
'cust1',  '202204', 5, 10,
)


df.1 %>% 
  group_by(customer, period) %>% 
  summarise(cost1 = sum(cost1, na.rm = T),
            cost2 = sum(cost2, na.rm = T),
            total = cost1 + cost2,
            pct   = cost1 / cost2) %>% 
  adorn_totals(where = 'row')

Expected output would be:

customer    period    cost1    cost2    total    pct
cust1       202201       5        10        15   .33333
cust1       202202       5        10        15   .33333
cust1       202203       5        10        15   .33333
cust1       202204       5        10        15   .33333  
Total                   20        40        60   .33333

Thanks in advance for advice.

>Solution :

Get the percentage per row, after adorn:

df.1 %>% 
  group_by(customer, period) %>% 
  summarise(cost1 = sum(cost1, na.rm = T),
            cost2 = sum(cost2, na.rm = T),
            total = cost1 + cost2) %>% 
  adorn_totals(where = 'row') %>% 
  mutate(pct = cost1/total)
# `summarise()` has grouped output by 'customer'. You can override using the
# `.groups` argument.
# customer period cost1 cost2 total       pct
#    cust1 202201     5    10    15 0.3333333
#    cust1 202202     5    10    15 0.3333333
#    cust1 202203     5    10    15 0.3333333
#    cust1 202204     5    10    15 0.3333333
#    Total      -    20    40    60 0.3333333