node-attribute graph layout for small-world networks
DESCRIPTION
Node-Attribute Graph Layout for Small-World Networks. Helen Gibson. Principal Supervisor: Dr. Paul Vickers 1 st Supervisor: Dr. Maia Angelova 2 nd Supervisor: Dr. Fouad Khelifi Previous Supervisor: Dr. Joe Faith. What is a Graph?. Relationships between concepts. - PowerPoint PPT PresentationTRANSCRIPT
Node-Attribute Graph Layout for Small-World Networks
Helen Gibson
Principal Supervisor: Dr. Paul Vickers1st Supervisor: Dr. Maia Angelova2nd Supervisor: Dr. Fouad Khelifi
Previous Supervisor: Dr. Joe Faith
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What is a Graph?
Relationships between concepts
Mathematics and Graph Theory
Graph
Graph Drawing
Information Visualisation
Network
Network Visualisation
http://visualcomplexity.com
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Examples
Social Networkshttp://on.fb.me/hy6dmb
Biological Networks
World Wide Webhttp://datamining.typepad.com/gallery/blog-map-gallery.html
IP Addresseshttp://circos.ca
https://www.fractalus.com/steve/stuff/ipmap/
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What’s the Problem?
Yeast interaction network in Gephi
It looks nice but is it doing anything useful?
Typical complaint: Giant-Hairball
Caused by force-directed algorithms
Old, but still popular and most commonly used
Connected nodes attract, other repel
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How Can This Be Solved?
Node Attributes
Example – Social Network
Node = PeopleLinks = Friendships
Attributes = age, gender, location, games they interact with, pages they had liked etc.
Typical Usage – As retinal variables
Use to tell us more information about the graph
Uses beyond retinal variables?
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Research Aims
Novel graph layout based on node-attributes
Many node attributes -> use a dimension reduction technique
Visual analysis of graphs
Visual Analytics - the science of analytical reasoning facilitated by interactive visual interfaces. [Thomas and Cook, 2005]
To further understand the connectivity and structure of the graph
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Node-Attributes to Dimensions
Attributes as a second set of linksNodes Attributes
Each attribute node is a dimension and existence of a link is a value for that dimension on that node
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Dimension Reduction and TPP
In visualisation: Many variables form a high-dimensional space reduce to
2 or 3 dimensions that can be seen on a display. Linear projections
Projection Pursuit: Finds the most ‘interesting’ projection Interestingness depends on the data
Targeted Projection Pursuit (TPP): Interactive Searches for a projection closest to a users desired view In following case, separation of the clusters as far as
possible.
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Small-World Networks
Networks that are: Highly clustered Smaller than average shortest path length
An Example: 4 clusters Small nodes are
attributes
Clustering – users’ most valued layout feature
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Force-Directed Graph+TPP
Comparison
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What’s Next?
‘How much better is the clustering?’
Real world domain applications
What do we learn about the data from the layout?
Evaluation
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Publications
Gibson, H. (2010) Data-driven layout for the visual analysis of networks. GROUP28: The XXVIII International Colloquium on Group-Theoretical Methods in Physics. Newcastle-upon-Tyne, July 2010. Poster presentation.
Gibson, H. , Faith, J. (2011) Node-attribute graph layout for small-world networks. 15th International Conference on Information Visualisation. London, July 2011