2  Introduction to R, RStudio, and Quarto

2.1 Learning Objectives

By the end of this week, you should be able to:

  • Install and open R, RStudio, and Quarto
  • Navigate the four-pane layout of RStudio
  • Create and run R scripts
  • Understand the differences between the console, script editor, and environment
  • Execute basic R operations and understand data types
  • Install and load R packages
  • Create and render a Quarto (.qmd) document to .pdf

2.2 Getting Started

R is a programming language designed for data analysis.
RStudio is an Integrated Development Environment (IDE) that makes working with R easier.
Quarto is a tool for creating reproducible documents that combine code and text.


2.3 Installing R, RStudio, and Quarto

  1. Install R: https://cran.r-project.org/
  2. Install RStudio: https://posit.co/download/rstudio-desktop/
  3. Install Quarto: https://quarto.org/docs/get-started/

When you open RStudio, you’ll see four panes:

  • Console – runs code interactively
  • Source – write and save scripts or Quarto documents
  • Environment/History – view and manage objects
  • Files/Plots/Packages/Help/Viewer – navigation and visualization tools

2.4 Introduction to Quarto

Quarto allows you to create documents that include both text and executable R code.

2.4.1 Your First Quarto Document

  1. In RStudio: File → New File → Quarto Document
  2. Replace the header with:
---
title: "My First Quarto Document"
author: "Your Name"
format: pdf
---
  1. Below the header, add:
x <- c(1, 2, 3, 4, 5)
mean(x)
[1] 3
  1. Click Render to produce a PDF file.

2.4.2 In-Class Quarto Exercise

  • Create a new Quarto document with:
    • A title, your name, and the date
    • A short paragraph of text
    • A code chunk that calculates the mean and standard deviation of a numeric vector
  • Render it to PDF and verify it works.

2.5 Basic R Concepts

2.5.1 Variables and Assignments

x <- 5
y <- 10
z <- x + y
z
[1] 15

2.5.2 Vectors and Functions

ages <- c(25, 30, 35, 40)
mean(ages)
[1] 32.5
sd(ages)
[1] 6.454972

2.5.3 Data Frames

name <- c("Alice", "Bob", "Charlie")
age <- c(25, 30, 35)
student_data <- data.frame(name, age)
student_data
     name age
1   Alice  25
2     Bob  30
3 Charlie  35

2.5.4 Inspecting Data

str(student_data)
'data.frame':   3 obs. of  2 variables:
 $ name: chr  "Alice" "Bob" "Charlie"
 $ age : num  25 30 35
summary(student_data)
     name                age      
 Length:3           Min.   :25.0  
 Class :character   1st Qu.:27.5  
 Mode  :character   Median :30.0  
                    Mean   :30.0  
                    3rd Qu.:32.5  
                    Max.   :35.0  
head(student_data)
     name age
1   Alice  25
2     Bob  30
3 Charlie  35

2.5.5 Comments and Help

# This is a comment
?mean  # Help for the mean function

2.5.6 Using Scripts and Console

  • Write your code in the script editor and run lines with Ctrl+Enter (Cmd+Enter on Mac)
  • Save scripts with the .R extension
  • Use the Console for quick exploration

2.5.7 Installing and Loading Packages

install.packages("tidyverse")

2.5.8 In-Class R Exercises

  1. Create a numeric vector of five numbers and calculate its mean, median, and standard deviation.
  2. Create a data frame with three columns (name, age, and major) and print its structure.
  3. Import a dataset from a URL using read.csv() and summarize it using summary().
my_vec <- c(10, 20, 30, 40, 50)
mean(my_vec)
[1] 30
median(my_vec)
[1] 30
sd(my_vec)
[1] 15.81139
df <- data.frame(
  name = c("Lily", "Mark", "Tom"),
  age = c(21, 22, 23),
  major = c("Biology", "Math", "History")
)
str(df)
'data.frame':   3 obs. of  3 variables:
 $ name : chr  "Lily" "Mark" "Tom"
 $ age  : num  21 22 23
 $ major: chr  "Biology" "Math" "History"
data <- read.csv("https://people.sc.fsu.edu/~jburkardt/data/csv/airtravel.csv")
summary(data)
    Month               X1958           X1959           X1960      
 Length:12          Min.   :310.0   Min.   :342.0   Min.   :390.0  
 Class :character   1st Qu.:339.2   1st Qu.:387.5   1st Qu.:418.5  
 Mode  :character   Median :360.5   Median :406.5   Median :461.0  
                    Mean   :381.0   Mean   :428.3   Mean   :476.2  
                    3rd Qu.:411.8   3rd Qu.:465.2   3rd Qu.:514.8  
                    Max.   :505.0   Max.   :559.0   Max.   :622.0  

2.6 Homework Preview

  • Create a .qmd document that:
    • Includes a title and your name
    • Demonstrates at least three code chunks
    • Shows basic statistics on a numeric vector
    • Imports a dataset, inspects it with str() and summary(), and writes one paragraph summarizing your findings
  • Render to PDF and submit to Canvas.

2.7 Next Steps

You now know how to run R scripts and render Quarto documents.
Next week, you’ll learn how to create data visualizations using ggplot2.