How to merge some table cells in Reactable

Question

I'm trying to create a reactable that will display statistics for a large number of categorical variables. The table should show the following columns: variable name, categories of variable, categories frequency, percentage, number of valid, and number of missing values.I would like to merge some table cells so that the values are not duplicated. I would like to merge: variable name, Valid Count and Missing Count. I could do this with java script, but I don't know that language.

This is the code I'm working on:

library(dplyr)
library(reachable)



calculate_summary <- function(x) {
  data_summary <- data.frame(Category = x) %>%
    count(Category, name = "Frequency") %>%
    mutate(Percent = (Frequency / sum(Frequency)) * 100,
           Valid_Count = sum(!is.na(Category)),
           Missing_Count = sum(is.na(Category))) %>%
    select(Category, Frequency, Percent, Valid_Count, Missing_Count)
  
  return(data_summary)
}



# Function to create the reactable
create_reactable <- function(data) {
  data_summary <- lapply(data, calculate_summary)
  combined_data <- do.call(rbind, data_summary)
  reactable(
    combined_data,striped = TRUE, resizable = TRUE, wrap = FALSE,
    style = list(
      fontFamily = "Helvetica"),
    
    columns = list(
      Category = colDef(name = "Category"),
      Frequency = colDef(name = "Count"),
      Percent = colDef(name = "Percent %"),
      Valid_Count = colDef(name = "Valid Count"),
      Missing_Count = colDef(name = "Missing Count")
    ),
    showPagination = TRUE
  )
}

# Example data
set.seed(123)
data <- data.frame(
  Variable = c("A", "B", "C", "D", "E", NA),
  Proba = c("A", "B", "C", "D", "E", NA)
  )
  


# Create the reactable using the function
reactable_data <- create_reactable(data)

# Display the reactable
reactable_data

With that code I get the following table design:

However, I would like to merge some cells.The table would look like this.

thanks!

Answer 1

Here is one possibility.

You could get this by using:

library(dplyr)
library(reactable)

calculate_summary <- function(x) {
    data_summary <- data.frame(Category = x) %>%
        count(Category, name = "Frequency") %>%
        mutate(Percent = (Frequency / sum(Frequency)) * 100,
               Valid_Count = ifelse(Category == "C", sum(!is.na(Category)), NA),
               Missing_Count = ifelse(Category == "C", sum(is.na(Category)), NA)) %>%
        select(Category, Frequency, Percent, Valid_Count, Missing_Count) 
    
    return(data_summary)
}

# Function to create the reactable
create_reactable <- function(data) {
    data_summary <- lapply(data, calculate_summary)
    combined_data <- do.call(rbind, data_summary) |> 
        tibble::rownames_to_column("Name") |> 
        mutate(Name = ifelse(Category != "C", "", Name)) |> 
        mutate(Name = gsub("\\..*","",Name)) 
    
    reactable(
        combined_data,striped = TRUE, resizable = TRUE, wrap = FALSE,
        style = list(
            fontFamily = "Helvetica"),
        
        columns = list(
            Category = colDef(name = "Category"),
            Frequency = colDef(name = "Count"),
            Percent = colDef(name = "Percent %"),
            Valid_Count = colDef(name = "Valid Count"),
            Missing_Count = colDef(name = "Missing Count")
        ),
        showPagination = TRUE
    )
}

# Example data
set.seed(123)
data <- data.frame(
    Variable = c("A", "B", "C", "D", "E", NA),
    Proba = c("A", "B", "C", "D", "E", NA)
)

# Create the reactable using the function
reactable_data <- create_reactable(data)

# Display the reactable
reactable_data