1. Data Visualization at Swansea University
Robert S. Laramee
Visual and Interactive Computing Group
Department of Computer Science
Swansea University 1
Visualization: An Introduction and Applications

2. Visualization: An Introduction and Applications
Overview
Introduction
Visualization: Background
Flow Visualization at Swansea University
Flow Visualization: Some Examples and Applications
Wrap Up 2
Visualization: An Introduction and Applications

3. Visualization: What is it?
“The purpose of computing is insight, not numbers” [Richard W. Hamming, 1962]
Visualization:
A tool that allows the user to gain insight into data.
To form a mental vision, image, or picture of (something not visible or present to the sight, or of an abstraction); to make visible to the mind or imagination [Oxford English Dictionary, 1989]
The non-fiction version of computer graphics 3
Visualization: An Introduction and Applications

4. Visualization – Background
Visualization = very old
Often an intuitive step to make something clearer, e.g., a graph
Data set sizes are ever-increasing making a graphical approach necessary
Classical (easy) approaches known from business graphics (Excel, etc.)
Visualization = its own scientific discipline since ~1987
First visualization conference: 1990
L. da Vinci ( )
1997: 4
Visualization: An Introduction and Applications

5. Visualization: An Introduction and Applications
User & Task
What is the problem?
User task/questions Visualization goals
Examples:
surgery planning
filter analysis
stock market vis.
[Oeltze et al., 2004]
[VRVis, 2004] 5
Visualization: An Introduction and Applications
[Shneiderman/Wattenberg, 2001]

6. Typical Visualization Tasks
Visualization is (can be) good for:
exploration
find the unknown, unexpected
hypothesis generation
analysis
confirm or reject hypotheses
information drill-down
presentation
communicate/disseminate results
[Seo/Shneiderman 2004]
[Doleisch et al., 2003]
[Bruckner/ Gröller 2005] 6
Visualization: An Introduction and Applications

7. Visualization: An Introduction and Applications
Visualization: 3 Foci
Three main sub-fields:
Volume Visualization
Flow Visualization
Information Visualization
Inherent
geometry
Scientific Visualization 3D nD
Usually no inherent geometry 7
Visualization: An Introduction and Applications

8. What is Flow Visualization?
a classic topic within scientific visualization
depiction of vector quantities (as opposed to scalar quantities)
applications include automotive, aerodynamics, turbomachinery, meteorology, oceanography medical visualization
Challenges:
to effectively visualize both magnitude + direction often simultaneously
large data sets
time-dependent data
What should be visualized? (data filtering/feature extraction) 8
Visualization: An Introduction and Applications

9. Flow Visualization: An Example
A (seemingly) straightforward way of visualizing vector fields is using glyphs. 9
Visualization: An Introduction and Applications

10. Flow Visualization: An Example
We designed an algorithm to solve the glyph placement problem. 10
Visualization: An Introduction and Applications

11. Flow Visualization: Example 2
We designed an algorithm to solve the streamline placement problem. 11
Visualization: An Introduction and Applications

12. Flow Visualization: Example 3
We designed an algorithm for the construction of stream surfaces. 12
Visualization: An Introduction and Applications

13. Flow Visualization: An Application
swirl motion: characterized by motion about cylinder-aligned axis
more stable (easier)
tumble motion: characterized by motion about axis orthogonal to cylinder
unstable, more difficult 13
Visualization: An Introduction and Applications

14. Flow Visualization: An Application
We designed visualizations especially for this application. 14
Visualization: An Introduction and Applications

15. Visualization Wrap-Up
Driven by the strongest human sense
Lots of different application fields
Serves different purposes
Exploration,analysis
presentation
Well developed research field
One of the research strengths in our department 15
Visualization: An Introduction and Applications

16. Visualization: An Introduction and Applications
Acknowledgements
Thank you for your attention!
Thanks to the following people:
Guoning Chen, Helwig Hauser, Tony McLoughlin, Zhenmin Peng, Benjamin Spencer, Daniel Weiskopf, Eugene Zhang
The research here is supported (in part) by EPSRC research grant EP/F002335/1.
Are there any questions? 16
Visualization: An Introduction and Applications