elastic hierarchies: combining treemaps and node-link diagrams
DESCRIPTION
Elastic Hierarchies: Combining Treemaps and Node-Link Diagrams. Shengdong Zhao, Michael J. McGuffin, Mark H. Chignell. University of Toronto. Hierarchies (Trees). Definition Data where cases relate to subcases Examples Family histories, ancestries File/directory systems on computers - PowerPoint PPT PresentationTRANSCRIPT
Elastic Hierarchies: Combining Treemaps and Node-Link Diagrams
Shengdong Zhao, Michael J. McGuffin, Mark H. Chignell
University of Toronto
University of Toronto2
Hierarchies (Trees)• Definition
• Data where cases relate to subcases
• Examples• Family histories, ancestries• File/directory systems on computers• Organization charts• Animal kingdom: phylum, genus• Object-oriented software classes
University of Toronto3
Common Tree Representations
Node-Link ContainmentAlignment,Adjacency
Outline
University of Toronto4
Common Tree Representations
Node-Link ContainmentAlignment,Adjacency
Outline
Node-LinkDiagram
University of Toronto5
Common Tree Representations
Node-Link ContainmentAlignment,Adjacency
Outline
TreemapNode-LinkDiagram
University of Toronto6
Common Tree Representations
Node-Link ContainmentAlignment,Adjacency
Outline
Treemap SunburstNode-LinkDiagram
University of Toronto7
Common Tree Representations
Node-Link ContainmentAlignment,Adjacency
Outline
Treemap SunburstNode-LinkDiagram Explorer
University of Toronto8
Tree Visualization Challenges
• Structure AND data within items• Scalability (exponential growth)• Context (when focus changes)• Multiple
hierarchies orpolyarchies
• Multiple foci
[Robertson]
[Furnas & Zacks]
University of Toronto9
Tree Visualization Challenges
• Different local properties• Topology (dense vs. sparse) • Data content (image vs. text)
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Tree Visualization Challenges
• Different local properties• Topology (dense vs. sparse) • Data content (image vs. text)
• Dynamic data• Hierarchies evolve • Adjustment required for content, context,
topology
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Single Representation Limitations
Treemap SunburstNode-LinkDiagram Explorer
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Single Representation Limitations
Treemap SunburstNode-LinkDiagram Explorer
• Structure vs. data within items
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Single Representation Limitations
Treemap SunburstNode-LinkDiagram Explorer
• Structure vs. data within items• Expressivity
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Single Representation Limitations
Treemap SunburstNode-LinkDiagram Explorer
• Structure vs. data within items• Expressivity• Static representation
University of Toronto15
Single Representation Limitations
Treemap SunburstNode-LinkDiagram Explorer
• Structure vs. data within items• Expressivity• Static representation
University of Toronto16
Node-Link & Treemap
Node-Link Treemap
Pros
• Familiar• Shows both structure and items
• Scalable, space efficient• Eases comparison of branch patterns
Cons• Hard to scale (100 nodes)
• Less familiar• Hard to see structure
University of Toronto17
Node-Link & Treemap
Node-Link Treemap
Pros
• Familiar• Shows both structure and items
• Scalable, space efficient• Eases comparison of branch patterns
Cons• Hard to scale (100 nodes)
• Less familiar• Hard to see structure
University of Toronto18
Node-Link & Treemap
Node-Link Treemap
Pros
• Familiar• Shows both structure and items
• Scalable, space efficient• Eases comparison of branch patterns
Cons• Hard to scale (100 nodes)
• Less familiar• Hard to see structure
University of Toronto19
Node-Link & Treemap
Node-Link Treemap
Pros
• Familiar• Shows both structure and items
• Scalable, space efficient• Eases comparison of branch patterns
Cons• Hard to scale (100 nodes)
• Less familiar• Hard to see structure
University of Toronto20
Solving the Problem
• Hybridize complementary representations to balance structure and scalability
University of Toronto21
Solving the Problem
• Hybridize complementary representations to balance structure and scalability
• Representational adaptations for branches and tasks
University of Toronto22
Solving the Problem
• Hybridize complementary representations to balance structure and scalability
• Representational adaptations for branches and tasks
• User manipulation and automatic adjustment
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Combine Multiple Representations
Node-Link
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Node-Link Treemap
Combine Multiple Representations
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Node-Link TreemapHybrid 1
Combine Multiple Representations
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Node-Link TreemapHybrid 1 Hybrid 2
Combine Multiple Representations
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… … …
Node-Link TreemapHybrid 1 Hybrid 2
Combine Multiple Representations
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… … …
Node-Link TreemapHybrid 1 Hybrid 2
Elastic Hierarchy:Entire set of adjustable hybrids of
multiple representations
Combine Multiple Representations
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Elastic Hierarchy
Node–Link Diagram
A tree of ~3500 nodes using Node-Link
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Elastic Hierarchy
Treemap
Same tree using Treemap
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Elastic Hierarchy
Same tree using Elastic Hierarchy
Elastic Hierarchy
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Elastic Hierarchy
Node–Link Diagram Treemap Elastic Hierarchy
• Elastic Hierarchy• Focus+context• Adaptability+user control• Multiple foci
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y
x
Taxonomy
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y
x Treemap (TM)
Node-Link (NL)
Taxonomy
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y
x Treemap (TM)
Node-Link (NL)
outside
inside
Taxonomy
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y
x Treemap (TM)
Node-Link (NL)
outside
inside
Taxonomy
NL outside NL …….(A)
TM outside NL …….(B)
NL outside TM …….(C)
TM outside TM …….(D)
NL inside TM …….(E)
TM inside TM …….(F)
NL inside NL …….(G)
TM inside NL …….(H)
University of Toronto37
y
x Treemap (TM)
Node-Link (NL)
outside
inside
Taxonomy
NL outside NL …….(A)
TM outside NL …….(B)
NL outside TM …….(C)
TM outside TM …….(D)
NL inside TM …….(E)
TM inside TM …….(F)
NL inside NL …….(G)
TM inside NL …….(H)
University of Toronto38
y
x Treemap (TM)
Node-Link (NL)
outside
inside
Taxonomy
NL outside NL …….(A)
TM outside NL …….(B)
NL outside TM …….(C)
TM outside TM …….(D)
NL inside TM …….(E)
TM inside TM …….(F)
Figure 4: here, the same tree is depicted 6 different ways (illustration): in A, with a traditional node-link diagram, in F, with a Treemap, and in B-E, with mixed, hybrid representations.
University of Toronto39
y
x Treemap (TM)
Node-Link (NL)
outside
inside
Taxonomy
Figure 4: here, the same tree is depicted 6 different ways (illustration): in A, with a traditional node-link diagram, in F, with a Treemap, and in B-E, with mixed, hybrid representations.
NL outside NL …….(A)
TM outside NL …….(B)
NL outside TM …….(C)
TM outside TM …….(D)
NL inside TM …….(E)
TM inside TM …….(F)
University of Toronto40
y
x Treemap (TM)
Node-Link (NL)
outside
inside
Taxonomy
Figure 4: here, the same tree is depicted 6 different ways (illustration): in A, with a traditional node-link diagram, in F, with a Treemap, and in B-E, with mixed, hybrid representations.
NL outside NL …….(A)
TM outside NL …….(B)
NL outside TM …….(C)
TM outside TM …….(D)
NL inside TM …….(E)
TM inside TM …….(F)
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Treemap Outside Node-Link
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Treemap Outside Node-Link
• Preserve top-level topology
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Treemap Outside Node-Link
• Preserve top-level topology
• Space filling at crowded lower levels
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Treemap Outside Node-Link
• Preserve top-level topology
• Space filling at crowded lower levels
• Pattern comparison among branches
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Treemap/Node-Link Outside Treemap
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• Focus+Context
Treemap/Node-Link Outside Treemap
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• Focus+Context• Multiple foci
Treemap/Node-Link Outside Treemap
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• Focus+Context• Multiple foci • Occlusion
Treemap/Node-Link Outside Treemap
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Node-Link Inside Treemap
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Node-Link Inside Treemap
• Local topology within context• But, has tight space constrains
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Node-Link Inside Treemap
• Local topology within context• But, has tight space constrains
• More space if resizing is allowed• But, resizing changes visual landmarks
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Working Together
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Working Together
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Implementation
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Implementation
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Implementation
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Implementation
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Implementation
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User Interactions
• Toggle between representations
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User Interactions
• Toggle between representations• Pan, zoom
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User Interactions
• Toggle between representations• Pan, zoom• Resize any subtree
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User Interactions
• Toggle between representations• Pan, zoom• Resize any subtree• Unambiguous selection within
Treemaps using tabs
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Elastic Hierarchy Video
University of Toronto64
Contributions
• Elastic representation
… … …
Node-Link TreemapHybrid 1 Hybrid 2
University of Toronto65
Contributions
• Elastic representation• Design space
… … …
Node-Link TreemapHybrid 1 Hybrid 2
Figure 4: here, the same tree is depicted 6 different ways (illustration): in A, with a traditional node-link diagram, in F, with a Treemap, and in B-E, with mixed, hybrid representations.
University of Toronto66
Contributions
• Elastic representation• Design space• Interaction techniques
… … …
Node-Link TreemapHybrid 1 Hybrid 2
Figure 4: here, the same tree is depicted 6 different ways (illustration): in A, with a traditional node-link diagram, in F, with a Treemap, and in B-E, with mixed, hybrid representations.
University of Toronto67
Future Work
• Empirical evaluation • Other useful elastic representations
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Acknowledgments
Ben Bederson, Ben Shneiderman, Ravin Balakrishnan, Maneesh Agrawala, Ed Chi, Amy Zhu, John Hancock, Joe Laszlo, Jim Chengming Cai, Noah Lockwood, Bowen Hui, anonymous reviewers, and other IML & DGP members at University of Toronto
University of Toronto69
Questions
Node–Link Diagram Treemap Elastic Hierarchy