2. Data Analysis & Visualization

Create charts and plots with AI using ggplot2.

Duration: 30 min

Tools: Cursor, R, ggplot2

What You’ll Learn

Build 2 quick visualizations using AI prompts
Understand what ggplot2 code looks like
Know when to use which chart type

Setup (2 minutes)

library(tidyverse)

penguins <- read_csv("data/penguins.csv") |> drop_na()

species_colors <- c(Adelie = "#4878d0", Chinstrap = "#ee854a", Gentoo = "#6acc65")

Chart 1: Bar Plot (Species Count)

Cursor prompt:

“Create a bar chart showing how many penguins are in each species. Use the species_colors palette. Add count labels on top of each bar.”

penguins |>
  count(species) |>
  ggplot(aes(x = species, y = n, fill = species)) +
  geom_col(width = 0.6, show.legend = FALSE) +
  geom_text(aes(label = n), vjust = -0.4, fontface = "bold") +
  scale_fill_manual(values = species_colors) +
  labs(title = "Penguin Count by Species", x = NULL, y = "Count") +
  theme_minimal()

Chart 2: Scatter Plot (Bill vs. Flipper Length)

Cursor prompt:

“Create a scatter plot with bill length on x-axis and flipper length on y-axis. Color by species using species_colors. Add title and axis labels.”

penguins |>
  ggplot(aes(x = bill_length_mm, y = flipper_length_mm, color = species)) +
  geom_point(alpha = 0.7, size = 2) +
  scale_color_manual(values = species_colors) +
  labs(
    title = "Bill Length vs. Flipper Length",
    x = "Bill Length (mm)",
    y = "Flipper Length (mm)",
    color = "Species"
  ) +
  theme_minimal()

Your Turn (10 minutes)

Pick one and use Cursor Chat to build it:

Option 1: Box plot of body mass by species
Option 2: Histogram of flipper length with overlays by species
Option 3: Simple table showing average measurements per species

Tip: Open Chat (Cmd+L), paste one of these, and let Cursor write the code:

"Create a [chart type] showing [what data]. Use species_colors. Add title and labels."

Key Takeaways

Use bar charts for counts across categories
Use scatter plots to see relationships between two measurements
Use box plots to compare distributions
Always specify colors, titles, and labels in your prompts

Resources

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