Sébastien Heymann <seb@gephi.org>

Exploratory Network Analysis

see the network1

1st graph viz tool: Pajek (1996)Vladimir Batagelj, Andrej Mrvar

interact in real time2

3

Gephi prototype (2008)group, filter, compute metrics...

size by rank, color by partition,label, curved edges, thickness...

build a visual language

Looking for Orderness in Data

Make varying 3 cursors simultaneously to extract meaningful patterns (statistical and structural properties)

MICRO level MACRO level

1 dimension N dimensions

T+0 T+N

at different levels

on multiple dimensions

at time scale

“Zoom” cursor on Quantitative Data

Global- connectivity- density- centralization

Local- communities- bridges between communities- local centers vs periphery

Individual- centrality- distances- neighborhood- location- local authority vs hub

MICRO level MACRO level

“Crossing” cursor on Qualitative Data

Social- who with whom- communities- brokerage- influence and power- homophily

Semantic- topics- thematic clusters

Geographic- spatial phenomena

1 dimension N dimensions

“Timeline” cursor on Temporal Data

Evolution of social ties

Evolution of communities

Evolution of topics

T+0 T+N

Mapping an Innovation CenterCollaborations on projects at Images et Réseaux

Themes and content

Actors

Territory

Franck Ghitalla & Ecole de Design de Nantes

Gephi in a Nutshell

« Like Photoshop™ for graphs. »

Helps data analysts to reveal patterns and trends,highlight outliers and tells story with their data.

• Network visualization platform

• Open source, supported by a community

• Built for performance and usability

• Extensible by plug-ins

• Windows, MacOS X, Linux

Gephi Community

ContributorsCommunities

Mathieu Bastian, Mathieu Jacomy, Eduardo Ramos Ibañez, Sébastien Heymann, Guillaume Ceccarelli, André Panisson, Antonio Patriarca, Cezary Bartosiak, Martin Škurla, Patrick McSweeney, Yi Du, Hélder Suzuki, Daniel Bernardes, Ernesto Aneiro, Keheliya Gallaba, Luiz Ribeiro, Urban Škudnik, Vojtech Bardiovsky, Yudi Xue

Nonprofit organization

Community Mission

Provide a “sustainable” software

Maintain the technical ecosystem

Build a business ecosystem

Face cutting-edge technological challenges with a long-term vision

Distribute the software in Open Source

Community Values

Open innovation: ideas and features come from the entire community.

Decisions are taken with transparency.

We consider this technology as a public good,and will keep it in open source.

Diversity of Usages

business leisure :-)

communication academic art

Diversity of Network Encoding

V = { a, b, c, d, e }E = { (a,b), (a,d), (b,c), (e,a), (c,e) }

Textual

a b c d ea - 1 - 1 -b - - 1 - -c - - - - 1d - - - - -e 1 - - - -

Tabular

<graph> <nodes> <node id=”a” /> <node id=”b” /> <node id=”c” /> <node id=”d” /> <node id=”e” /> </nodes> <edges> <edge source=”a” target=”b” /> <edge source=”a” target=”d” /> <edge source=”b” target=”c” /> <edge source=”e” target=”a” /> <edge source=”c” target=”e” /> </edges></graph>

XMLGraphical

and many others...

Software I/O

} >

graph streaming

databases

file

file

CSVPajek NETGuess GDFGEXFGraphMLGraphviz DOTUCInet DLNetdrawVNATulip TLPExcel Spreadsheet

MySQL PostgreSL

SQL ServerNeo4j

CSVPajek NETGuess GDFGEXFGraphMLExcel SpreadsheetSVGPDFPNG

user input