Data Visualization

Andrew Irwin, a.irwin@dal.ca

Math & Stats, Dalhousie University

2024-01-09

SARS-CoV-2 variants

Each color is a variant. Data from covariants.org

What stories were told in those images?

Stories

  • CO2 in the atmosphere varies through the year, has increased 100 ppm over 60 years and is higher than it has been for 800,000 years
  • Arctic sea ice volume has shrunk by more than 50% and the fall will be ice-free soon
  • Fertility decreases as income increases, regardless of the country
  • Is it going to rain? Turn cooler?

Stories

  • Annual cycle of temperature is about 24°C. Daily range is about 8°C. Daily variation over years is 7-14°C.
  • Napoleon’s army shrunk by 99% in their Russian campaign
  • Military deaths in the Crimean war were largely from preventable causes
  • Deaths from cholera were centred on one location in Broad St.
  • There have been at least 7 major covid variants, persisting for 4-6 months each

What is data visualization?

What is data visualization?

  • Turn data into images

  • Iterative process to explore data

  • Filter, summarize, and present data

What is the purpose of data visualization?

  • Summarize data compactly

  • Leverage vision machinery in brain

  • Helps you tell a story with data

  • A familiar visualization tells a story “by itself”

What makes a good visualization?

  • Effective communication aid

  • Memorable & understandable

  • Aesthetically pleasing - nothing confusing, jarring, or out of place

Suggested reading

  • Course notes: Welcome

  • Course notes: Invitation to Data Visualization

  • Wilke: Chapter 29: Telling a story and making a point

  • Video: Hans Rosling’s TED talk (linked in “Invitation”)

  • Video: Excerpt from Claus Wilke’s talk for the Santa Fe Institute (linked in “Invitation”)

Task

  • Prepare a short report on two visualizations you like or could improve on.

  • Details in Course notes (Detailed outline, Evaluation)