Introduction to R Programming

Enhanced Web Version - Demo

Introduction to R Programming

A Modern, Interactive Guide for Livestock Genomics Research

CTLGH Training 2026 Beginner Friendly

Demo Preview

This is a preview showing the first two sections of the R tutorial with enhanced web design and styling.

---

1 Learning Objectives

📊

R and R Markdown

Understand the basics of R programming and R Markdown for reproducible research

🔢

Algebra in R

Perform mathematical operations and work with variables

📦

Libraries & Packages

Install and load R packages to extend functionality

📁

File Management

Set working directories and organize your project files

📈

Data Visualization

Create publication-quality plots and graphics

💾

Data Export

Write data files and organize reproducible scripts

---

2 What is R?

About R

R is a free software environment for statistical computing and graphics. One of its key strengths is the ability to create publication-quality plots with minimal effort.

RStudio is a flexible and multi-functional open-source IDE (integrated development environment) that provides a graphical front-end to work with R more efficiently.

Open Source

Free forever, supported by a global community

How R Works

R is used by typing commands into the Console after the > prompt. Commands can be separated using ; or by pressing Enter for a new line.

Pro Tip: To run code in R Markdown, click anywhere in the code chunk and then click Run → Run Current Chunk, or use Ctrl + Shift + Enter (Windows) or Cmd + Shift + Return (Mac).

Your First R Command

Try running this code:

"hello world!"

## [1] "hello world!"

# or use the print function
print("hello world!")

## [1] "hello world!"

Learning Note: Like learning any new language, if you encounter errors or aren't sure how to do something, you can search online for help. R has an extensive community with many forums and resources!

---

Getting Help in R

R has built-in documentation for every function. Here are several ways to access help:

Using help()

help("print")

Access detailed documentation for any function

Using ?

?print

Quick shortcut to access help pages

# Method 1: Detailed help
help("print")

# Method 2: Quick help
?print

# Method 3: See examples
example("print")

# Method 4: Start HTML help browser
help.start()

Online Resources

Here are essential R resources:

R Documentation
Comprehensive documentation on R tools and packages
rdocumentation.org →

Stack Overflow
Q&A community for programming challenges
stackoverflow.com →

RStudio Cheatsheets
Quick reference guides for common tasks
rstudio.github.io →

Tidyverse
Collection of modern R packages for data science
tidyverse.org →

---

R as a Calculator

R can perform all standard mathematical operations:

# Simple addition
1 + 1

## [1] 2

Try it yourself: Type calculations directly in the R Console at the bottom of RStudio to see instant results!

Key Points

RStudio Interface
Better manage scripts, data, and figures

R Markdown
Combine code and documentation

Reproducible
Share and replicate your analysis

---

Ready for More?

This is just a preview of Sections 1 & 2. The complete tutorial includes:

Variables & Calculations

Vectors & Matrices

Data Manipulation

Advanced Visualization