script for subset a CSV file based on different groups in a column and save the subsets as separate CSV files

library(dplyr)

library(dplyr)
library(purrr)

# Read the CSV file
data <- Bigfile.csv

# Define the column containing the groups
group_column <- "sample.group"

# Get unique group values
group_values <- unique(data[[group_column]])

# Create a directory to save the subsets
output_directory <- "/Users/usri/Desktop/JUNE25/output.directory"
dir.create(output_directory, showWarnings = FALSE)

# Subset the data and save as separate CSV files
walk(group_values, function(group_value) {
    subset <- data %>%
        filter(.data[[group_column]] == group_value)
   
    output_file <- file.path(output_directory, paste0(group_value, ".csv"))
    write.csv(subset, output_file, row.names = FALSE)
})