Add row in etable from expss R package - r

Question

I want to add rows at specific place to expss output etable. I did that with some brute force method which always add the row at the start of etable. Any method to add rows at specific place.
library(tidyverse)
library(expss)
test1 <-
mtcars %>%
tab_cells(cyl) %>%
tab_cols(vs) %>%
tab_stat_cpct() %>%
tab_pivot()
test1 %>%
tibble() %>%
tibble::add_row(.data = tibble("", test1[2, -1]/test1[1, -1]*100) %>%
set_names(names(test1))
, .before = 3)

Answer 1

Not sure there's a simple method exported with expss, but we can use expss::add_rows() with a simple custom function to split a table to accomplish this.
insert_row <- function(tbl, where, ...) {
args <- c(...)
tbl1 <- tbl[1:where,]
tbl2 <- tbl[(where+1):nrow(tbl),]
tbl1 %>%
add_rows(args) %>%
add_rows(tbl2)
}
insert_row(test1, 2, c("cyl|4", 300, 40))
| | | vs | |
| | | 0 | 1 |
| --- | ------------ | ---------------- | ---------------- |
| cyl | 4 | 5.55555555555556 | 71.4285714285714 |
| | 6 | 16.6666666666667 | 28.5714285714286 |
| | 4 | 300 | 40 |
| | 8 | 77.7777777777778 | |
| | #Total cases | 18 | 14 |

Answer 2

Solution based on #caldwellst code but with automatic ratio calculation:
insert_ratio <- function(tbl, where) {
if(is.character(where)) {
# if where is character we search it in the rowlabels
where = grep(where, tbl[[1]], fixed = TRUE)[1]
}
isTRUE(where>1) || stop("'where' should be greater than 1 for ratio calculation.")
isTRUE(where<=NROW(tbl)) || stop("'where' should be less or equal than number of rows in the table.")
tbl1 <- tbl[1:where,]
to_insert = c(row_labels = tbl[[1]][where], tbl[where, -1]/tbl[where - 1, -1]*100)
tbl2 <- tbl[(where+1):nrow(tbl),]
tbl1 %>%
add_rows(to_insert) %>%
add_rows(tbl2)
}
insert_ratio(test1, 2)
# | | | vs | |
# | | | 0 | 1 |
# | --- | ------------ | ----- | ---- |
# | cyl | 4 | 5.6 | 71.4 |
# | | 6 | 16.7 | 28.6 |
# | | | 300.0 | 40.0 |
# | | 8 | 77.8 | |
# | | #Total cases | 18.0 | 14.0 |
insert_ratio(test1, "cyl|6")
# the same result
UPDATE
Ratio calculation is moved to separate function:
ratio = function(tbl, where, label = NULL){
if(is.character(where)) {
# if where is character we search it in the rowlabels
where = grep(where, tbl[[1]], fixed = TRUE)[1]
}
isTRUE(where>1) || stop("'where' should be greater than 1 for ratio calculation.")
isTRUE(where<=NROW(tbl)) || stop("'where' should be less or equal than number of rows in the table.")
if(is.null(label)) label = tbl[[1]][where]
c(row_labels = label, tbl[where, -1]/tbl[where - 1, -1]*100)
}
insert_row = function(tbl, where, row) {
if(is.character(where)) {
# if where is character we search it in the rowlabels
where = grep(where, tbl[[1]], fixed = TRUE)[1]
}
isTRUE(where<=NROW(tbl)) || stop("'where' should be less or equal than number of rows in the table.")
first_part = seq_len(where)
tbl1 <- tbl[first_part,]
tbl2 <- tbl[-first_part,]
tbl1 %>%
add_rows(row) %>%
add_rows(tbl2)
}
insert_row(test1, 2, ratio(test1, 2))
insert_row(test1, "cyl|6", ratio(test1, "cyl|6"))