Information Visualization Alvitta Ottley Washington University in - PowerPoint PPT Presentation

CSE 557A | March 01, 2018 Information Visualization Alvitta Ottley Washington University in St. Louis Slides credit: Mariah Meyer, University of Utah

Gra Graph Da Data

Gra Graph Da Data What can you represent as a graph?

De Definition Graphs represent connections or relationships Social network • • Software execution (call graph) • Gene expression • Financial transactions WWW • US telephone system • One of the oldest and most studied areas of information visualization

Wh What at Mak akes es a a Grap aph? Node-Link Diagram • Vertices (nodes) • Edges (links) Adjacency Matrix: • 1: 2 • 2: 1, 3 • 3: 2

Ad Adjace cency ncy Matrix ix

Le Les Mi Misé sérables Ch Characters Co Co-occu occurrence ce

Id Identifying pa g patterns Henry 2006

Ca Can you think of sho shortcomings o s of t thi his s ap approach ach?

No Node-Li Link D Diagrams

Te Term rminology Directed vs. Undirected • • Cyclic vs. Acyclic Degree of a vertex • • In-degree Out-degree • Weights on edges •

Term Te rminology 1 Directed vs. Undirected • • Cyclic vs. Acyclic 2 3 Degree of a vertex • • In-degree 1 Out-degree • Weights on edges • 2 3

Term Te rminology 1 Directed vs. Undirected • • Cyclic vs. Acyclic 2 3 Degree of a vertex • • In-degree 1 Out-degree • Weights on edges • 2 3

Te Term rminology 1 Directed vs. Undirected • • Cyclic vs. Acyclic 2 3 Degree of a vertex • • In-degree Out-degree • Weights on edges •

Te Term rminology 1 Directed vs. Undirected • • Cyclic vs. Acyclic 2 3 Degree of a vertex • • In-degree Out-degree • Weights on edges •

More T Mo Termi minolo logy gy Centrality Measures: • • Degree Centrality • How many neighbors does a vertex have? Betweenness Centrality • • How often does a vertex appear in paths between other nodes? • Closeness Centrality • How quickly can a node reach all other nodes in the graph? • Eigenvector Centrality Google PageRank (assumes directed graph) •

Gra Graphs vs. Tre rees Tree is a special case of a general graph • • There are no cycles in a tree Edges are (usually) directed or are implicitly directed • Special designations for root, leaves, etc. •

Cha Challenge ges i s in G Graph V h Visu sualiza zation Graph layout and position • • Related to your studio! Navigation / Interaction • • How to support a user in understanding all the relationships in the graph Scale • • What happens if the graph has 10 nodes? 1,000 nodes? 1,000,000 nodes?

Co Comparing Representations: Which do you pre prefer r and d why?

De Dealing wi with lar large an and d me messy graph phs

Te Techniques for r Gra raph Simplification

Mo Motif G Gly lyph phs

Mo Motif G Gly lyph phs

Ed Edge Bundlin ing

Wh What t are e th the e str tren ength ths and d wea eakn knes esses es of th thes ese e approaches es?

How How do o you ou cho choose se a a lay layout?

Hi Hierarchy

Ge Geos ospatial

Wh What t if th there is is n no in intrin insic ic la layout? ut?

Fo Force ce-di dire rected d layout

Fo Force Model

Algo Algorit ithm

d3 d3 example

St Studio: io: Su Suppor ortin ing I Interaction ion a and Und Understand nding ng. How would you add interaction to a force- direction graph?