🚀 Getting Started with R: Preparing for WPD

Welcome! Before we can use the World Panel Data (WPD) package, we need to set up our working environment. This guide assumes you have no prior experience with R or programming. We’ll walk through everything step by step.

📥 Part 1: Setting Up Your Environment

What is R and RStudio?

Before we start installing anything, let’s understand what we’re working with:

R is a programming language specifically designed for statistical computing and data analysis. Think of it as a powerful calculator that can handle large amounts of data.
RStudio is what we call an Integrated Development Environment (IDE) for R. Think of it as a sophisticated text editor that makes working with R much easier. It’s like Microsoft Word, but for writing R code instead of documents.

Installing R

Windows Installation

Open your web browser and visit the R Project Website
Look for the “Download R for Windows” link and click it
Click on “base” (this is what you need for a first-time installation)
Click the big download link at the top (it will say something like “Download R-4.x.x for Windows”)
Once downloaded, double-click the installer file (.exe)
Important: When prompted, select “Yes” to all default settings
- ⚠️ Make note of where R is being installed (usually C:Files-4.x.x)

macOS Installation

Visit the R Project Website
Click “Download R for macOS”
If you have a recent Mac (2021 or later), look for “Apple silicon arm64 build”
- For older Macs, use the “Intel 64-bit build”
Download the .pkg file
Double-click the downloaded file
Follow the installation steps, keeping all default settings

Linux Installation

For Ubuntu/Debian:

# Open terminal (Ctrl + Alt + T) and type:
sudo apt update
sudo apt install r-base r-base-dev

For Fedora:

sudo dnf install R

For other distributions, check the R Installation Guide

Installing RStudio

After installing R, install RStudio:

Visit the RStudio Download Page
Scroll down to find the installer for your operating system
Download and run the installer
Keep all default settings during installation

Verifying Your Installation

Let’s make sure everything is working:

Open RStudio (not R itself)
In the bottom panel (called the “Console”), type:
```
1 + 1
```
Press Enter. You should see:
```
[1] 2
```

If you see this result, congratulations! Your installation is working.

📦 Part 2: Understanding R Packages

What are R Packages?

R packages are collections of additional functions and data that extend R’s capabilities. Think of R as a smartphone, and packages as apps you can install to add new features.

There are two main ways to install R packages:

From CRAN (The Comprehensive R Archive Network)
- This is like an official app store for R
- Most packages are available here
- Installation is simple and standardized
From GitHub
- This is like installing apps directly from developers
- Gives access to the latest versions
- Requires an extra package called devtools to install

Installing Packages from CRAN

Let’s practice by installing a popular package called ggplot2:

# Type this in the RStudio console:
install.packages("ggplot2")

# You might see some text output during installation
# When it's done, load the package:
library(ggplot2)

If you see any red text (called “errors” or “warnings”), don’t panic! Here are some common issues:

“Could not find package”: Check your spelling
“Permission denied”: On Windows, try running RStudio as administrator
“Dependencies”: Say yes if asked to install additional packages

Installing Packages from GitHub

Installing from GitHub requires more steps:

First, install the devtools package:
```
install.packages("devtools")
```
Load devtools:
```
library(devtools)
```
Now you can install packages from GitHub. For example, to install WPD:
```
install_github("benjaminpeeters/WPD")
```

Understanding Package Messages

When installing packages, you might see different types of messages:

Notes (black text): Just information, nothing to worry about
Warnings (yellow/orange text): Something to be aware of, but not critical
Errors (red text): Something went wrong and needs to be fixed

Example warning you might see:

Warning: package 'ggplot2' was built under R version 4.1.2

This is usually fine - it just means the package was tested with a different R version.

🔧 Part 3: Basic R Usage

Before we start using WPD, let’s learn some R basics:

The RStudio Interface

RStudio has four main panels: 1. Source Editor (top-left): Where you write your code 2. Console (bottom-left): Where you run code and see results 3. Environment (top-right): Shows your data and variables 4. Files/Plots/Help (bottom-right): Shows files, plots, and documentation

Creating an R Script

Click File → New File → R Script (or press Ctrl+Shift+N)
A new blank document appears in the Source Editor
Save it (Ctrl+S) with a name like “my_first_script.R”

Running Code

There are several ways to run code: - Type directly in the console and press Enter - In a script, click “Run” or press Ctrl+Enter to run the selected line(s) - Select multiple lines to run them together

Try these examples:

# Basic calculations
2 + 2
10 * 5
100 / 10

# Creating variables
my_number <- 42
my_text <- "Hello, R!"

# Display variables
print(my_number)
print(my_text)

# Create a list of numbers
numbers <- c(1, 2, 3, 4, 5)
mean(numbers)  # Calculate average
sum(numbers)   # Calculate sum

Getting Help

R has a built-in help system:

# Get help about a function
?mean
help(sum)

# Search help
??regression  # Search for topics about regression

✨ Practice Exercises

Try these exercises to build your skills:

Basic R Operations:

# Calculate these expressions:
# 1. 15 plus 7
# 2. 20 divided by 4
# 3. 3 times 8
# 4. 10 minus 3

Working with Variables:

# Create variables for:
# 1. Your age
# 2. Your name
# 3. A list of five numbers
# Then try to calculate the mean of your number list

Package Installation:

# Try to:
# 1. Install the 'dplyr' package from CRAN
# 2. Load the package using library()
# 3. Check if you get any errors

Getting Help:

# Look up help for these functions:
# 1. sqrt
# 2. paste
# 3. length
# Read the examples in each help page

🌐 Additional Resources

🤝 Getting Help

When You’re Stuck:
- Google the error message (this is what professionals do!)
- Check Stack Overflow
- Join the RStudio Community
Best Practices When Asking for Help:
- Share the exact error message
- Show the code that caused the error
- Explain what you were trying to do
- Mention your operating system and R version

Remember: Everyone was a beginner once! Don’t be afraid to ask questions or make mistakes - that’s how you learn.

In the next vignette, we’ll start using WPD to analyze economic data. Make sure you’re comfortable with these basics before moving on.

R Basics: Getting Ready for WPD

Benjamin Peeters

2024-11-14