Creating a user-defined total with grand_summary_rows() - r

Question

I have a table that looks like this:
category family amount
<chr> <chr> <chr>
1 SALES ONLINE SALES 47
2 SALES IN STORE 72
3 COGS LABOR 28
4 COGS TAXES 35
5 COGS WORKERS COMP 24
6 COGS BENEFITS 33
7 EXPENSE AUTOMOBILE 44
8 EXPENSE RENT 12
9 EXPENSE TELEPHONE 26
I am trying to create a gt table from this so I have created this code:
library(tidyverse)
library(gt)
category <- c(rep("SALES",2),
rep("COGS", 4),
rep("EXPENSE",3)
)
family <- c("ONLINE SALES","IN STORE","LABOR","TAXES","WORKERS COMP","BENEFITS",
"AUTOMOBILE", "RENT","TELEPHONE")
amount <- c(47,72,28,35,24,33,44,12,26)
output <- as_tibble(cbind(category,family,amount)) %>%
mutate(amount= as.numeric(amount)) %>%
gt(rowname_col = 'family',
groupname_col = 'category') %>%
row_group_order(c("SALES","COGS", "EXPENSE")) %>%
summary_rows(groups = TRUE,
columns = 'amount',
fns = list(
Total = ~sum(.,na.rm = TRUE)
))
output
How do you get the overall total of SALES-COGS-EXPENSE using the grand_summary_rows() function while all of the amounts are still positive?

Answer 1

if I have correctly understood your request you can use the code below:
output2 <- as_tibble(cbind(category,family,amount)) %>%
mutate(amount= as.numeric(amount)) %>%
gt(rowname_col = 'family', groupname_col = 'category') %>%
summary_rows(groups = TRUE,
columns = 'amount',
fns = list(
Total = ~sum(.,na.rm = TRUE)
)) %>%
grand_summary_rows(
columns = c("family","category","amount"),
fns = list(
"Grand Total" = ~sum(.,na.rm = TRUE)),
formatter = fmt_number,
use_seps = FALSE
)
output2
################### EDIT ###################
The only way I found from the documentation is to create a custom aggregation function. Here's the full working example with the output printscreen.
customFunc <- function(data) {
salesSum <- sum(subset(data$`_data`[,c("amount")], category == 'SALES'))
cogsSum <- sum(subset(data$`_data`[,c("amount")], category == 'COGS'))
expenseSum <- sum(subset(data$`_data`[,c("amount")], category == 'EXPENSE'))
return (salesSum - cogsSum - expenseSum)
}
data <- as_tibble(cbind(category,family,amount)) %>%
mutate(amount= as.numeric(amount)) %>%
gt(rowname_col = 'family', groupname_col = 'category')
output3 <- data %>%
summary_rows(groups = TRUE,
columns = 'amount',
fns = list(
Total = ~sum(.,na.rm = TRUE)
)) %>%
grand_summary_rows(
columns = c("family","category","amount"),
fns = list(
"Grand Total" = ~customFunc(data)),
formatter = fmt_number,
use_seps = FALSE
)
output3