Save DataFrame as Data Table in R

This document provides an R function to save a DataFrame as a Data Table file. The function is designed to include all necessary imports, input validation, and inline comments explaining each step. A usage example is also provided at the end.

Prerequisites

Ensure you have the necessary libraries installed. You can install required packages using:

install.packages("data.table")

Function Definition

# Load necessary library
library(data.table)

#' Save DataFrame as Data Table
#'
#' This function saves a given DataFrame as a Data Table in a specified file path.
#'
#' @param df DataFrame. A data frame to be saved as a data table file.
#' @param file_path Character. A string representing the file path where the data table will be saved.
#' @return None. The function saves the data table to the specified path.
#' @examples
#' df <- data.frame(x = 1:10, y = 11:20)
#' save_as_data_table(df, "example_data_table.csv")
save_as_data_table <- function(df, file_path) {
  # Input validation
  if (!is.data.frame(df)) {
    stop("Input is not a data frame.")
  }

  if (!is.character(file_path) || length(file_path) != 1) {
    stop("File path should be a single string.")
  }
  
  # Convert data frame to data table
  data_table <- as.data.table(df)
  
  # Write data table to file
  fwrite(data_table, file_path)
  
  cat("Data table successfully saved to", file_path, "\n")
}

# Usage example
df <- data.frame(x = 1:10, y = 11:20)
save_as_data_table(df, "example_data_table.csv")

Function Breakdown

1. Imports and Libraries:

   • library(data.table): Includes the data.table package to provide optimized functions for large data sets.

2. Function Documentation:

   • Detailed docstring provides an overview of the function's purpose, parameters, return type, and examples.

3. Input Validation:

   • Checks if df is actually a DataFrame.
   • Validates that file_path is a valid single string.

4. Conversion and Saving:

   • Uses as.data.table() to convert the DataFrame to a Data Table.
   • fwrite() writes the data table to the specified file path.

5. Output Message:

   • Confirmation message displayed after successful operation.

Usage Example

To use the function, create a DataFrame and specify the file path where you want to save the Data Table:

# Data frame creation
df <- data.frame(A = 1:5, B = letters[1:5])

# Saving as data table
save_as_data_table(df, "my_data_table.csv")

This will save df as a data table in the file my_data_table.csv.

Additional Resources

For more advanced data manipulation and handling functionalities in R, consider exploring resources available through the Enterprise DNA Platform.

That's it! Your DataFrame is now efficiently saved as a Data Table, maintaining the best practices in R for input handling and documentation.