Creating Packages | R Packages | R Programming Tutorial

Introduction

In R programming, creating packages is a way to bundle your functions, data, and documentation together. This enables you to share your work with other R users or deploy your functionality in different projects easily. This tutorial will guide you through the entire process of creating an R package from start to finish.

Setting Up Your Environment

Before you start creating a package, ensure you have R and RStudio installed on your machine. You also need to install the 'devtools' package, which simplifies package development.

Install 'devtools' by running the following command:

install.packages("devtools")

Creating a Package Structure

Use the 'create' function from the 'devtools' package to set up a new package. Replace "mypackage" with your desired package name.

Run this command in R:

devtools::create("mypackage")

This command creates a directory named "mypackage" containing the necessary files and subdirectories for your package including NAMESPACE, DESCRIPTION, and a folder for R scripts.

Adding Functions

Inside the "mypackage/R" directory, create an R script file (e.g., my_function.R) and write your functions there. For example, let’s create a simple function that adds two numbers:

my_function.R:

add_numbers <- function(x, y) {
return(x + y)
}

Documenting Your Functions

Documentation is crucial for package usability. Use Roxygen2 comments to document your functions. Above your function, add comments that describe the function, its parameters, and return value.

Example documentation for the add_numbers function:

#' Add two numbers
#'
#' @param x First number
#' @param y Second number
#' @return Sum of x and y
#' @export
add_numbers <- function(x, y) {
return(x + y)
}

Building and Installing Your Package

After adding your functions and documentation, you can build your package using the following command in R:

Build the package:

devtools::build()

To install your package, you can use the install function:

Install the package:

devtools::install("mypackage")

Testing Your Package

It is essential to test your package to ensure that everything works as expected. You can load your package and call your function as follows:

Load and test your package:

library(mypackage)
result <- add_numbers(3, 5)
print(result)

This should output 8 if everything is correct.

Conclusion

Creating R packages is a powerful way to organize and share your work. By following this tutorial, you should be able to create a simple R package, add functions, document them, and test your package. As you progress, you can explore more advanced features such as vignettes, unit tests, and continuous integration.

Creating R Packages