The grammar of graphics

Introduction to Data Visualization with ggplot2

Rick Scavetta

Founder, Scavetta Academy

The quick brown fox jumps over the lazy dog

The quick brown fox jumps over the lazy dog

Grammar of graphics

• Plotting framework
• Leland Wilkinson, Grammar of Graphics, 1999
• 2 principles
  • Graphics = distinct layers of grammatical elements
  • Meaningful plots through aesthetic mappings

The three essential grammatical elements

Element	Description
Data	The data-set being plotted.
Aesthetics	The scales onto which we map our data.
Geometries	The visual elements used for our data.

Course 1: core competency

Element	Description
Data	The data-set being plotted.
Aesthetics	The scales onto which we map our data.
Geometries	The visual elements used for our data.
Themes	All non-data ink.

The seven grammatical elements

Element	Description
Data	The data-set being plotted.
Aesthetics	The scales onto which we map our data.
Geometries	The visual elements used for our data.
Themes	All non-data ink.
Statistics	Representations of our data to aid understanding.
Coordinates	The space on which the data will be plotted.
Facets	Plotting small multiples.

Jargon for each element

Course 2: Tools for EDA

• Remaining 3 layers
• Best practices for Data Viz

Let's practice!

Introduction to Data Visualization with ggplot2