ggplot2 Introduction

Introduction

ggplot2 is R's most popular visualization package based on the Grammar of Graphics. It creates elegant, customizable plots.

Basic Structure

library(ggplot2)

ggplot(data, aes(x = variable1, y = variable2)) +
  geom_point()

Quick Plots

# Using qplot
qplot(x, y, data = df)
qplot(x, data = df, geom = "histogram")

Core Components

ggplot(df, aes(x = var1, y = var2)) +

  # Data
  # Aesthetics (aes)
  
  # Geometries (geom)
  geom_point()
  
  # Labels
  labs(title = "Title", x = "X", y = "Y")
  
  # Theme
  theme_minimal()

Aesthetic Mappings

ggplot(df, aes(x = var1, y = var2, 
               color = category,
               size = value,
               shape = type,
               alpha = 0.5)) +
  geom_point()

Summary

ggplot2 provides a powerful grammar for creating visualizations. Build plots layer by layer.