Sébastien Heymann <[email protected]>
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