Transcript Document 7411853

SIMS 247: Information Visualization
and Presentation
jeffrey heer
Tree Visualization
Oct 26, 2005
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today
• administrivia
• tree visualization
• design exercise
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administrivia
• How are project proposals coming along?
• If you have questions, concerns, or are
seeking advice, come to my office hours!!
– Today, 1-2:30pm - 210 South Hall
– Appointments also possible
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Graphs and Trees
• Graphs:
– Representations of structured, connected data
– Consist of a set of nodes (data) and a set of edges
(relations)
• Trees:
– Graphs with a specific structure
• connected graph with n-1 edges
– Representations of data with natural hierarchy
– Nodes are either parents or children
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Tree Visualization
• File Hierarchy
in computer
• Need to navigate through
the hierarchy to find a
particular file
• Two common problems:
“Where am I?” and
“Where is the file that I
am looking for?”
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Tree Visualization
• Organizational Chart
http://www.cs.umd.edu/hcil/spacetree/
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Tree Visualization
• Tournaments
taken from “To Draw A Tree” by Pat Hanrahan
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Tree Visualization
• Family Trees
taken from “To Draw A Tree” by Pat Hanrahan
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Tree Visualization
• Family Trees
taken from “To Draw A Tree” by Pat Hanrahan
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Tree Visualization
• Evolutionary
Trees
taken from “To Draw A Tree” by Pat Hanrahan
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Tree Visualization
• Evolutionary
Trees
taken from “To Draw A Tree” by Pat Hanrahan
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Tree Visualization
• Assembly Instructions
taken from “To Draw A Tree” by Pat Hanrahan
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Tree Visualization Approaches
• Node-Link Diagrams
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Reingold-Tilford Layout
Radial Layout
Indented Layout
Cone Trees & Balloon Trees
Hyperbolic Trees
• Enclosure Diagrams
– TreeMaps
– Voronoi TreeMaps
– Jigsaw Maps
• Alternative Approaches
– Icicle Trees
– Sunburst Diagrams
– Cascaded Lists
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Reingold-Tilford Layout
Top-down layout
Uses separate
dimensions for
breadth and depth
breadth --> width
depth --> height
tidier drawing of trees - reingold, tilford
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Radial Layout
Places children on
increasing larger radii
A top-down layout
converted into polar
co-ordinates
breadth --> angle
depth --> radius
gnutellavision – yee, fisher, dhamija, hearst
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Indented Layout
Places all items along vertically
spaced rows
Uses indentation to show parent
child relationships
Breadth and depth end up
fighting for space resources
breadth --> height, locality
depth --> height, indentation
microsoft file explorer
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Cone Trees
Top-down tree layout
in three dimensions
Shadows provide 2D
structure
Can also make
“Balloon Trees” – 2D
version of ConeTree
cone tree – robertson, mackinlay, and card
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Balloon Trees
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
• flattened cone trees
herman, melancon, and marshall
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Hyperbolic Trees
Places nodes using
hyperbolic geometry
This is then projected
into “normal” space
h3 viewer – tamara munzner
hyperbolic tree – lamping, rao
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TreeMaps
Space-filling
technique that divides
space recursively
Segments space
according to ‘size’ of
children nodes
map of the market – wattenberg / smartmoney.com
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Voronoi TreeMaps
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
voronoi treemaps - balzer and deussen
• TreeMaps that divide space using arbitrary
polygons based on Voronoi tesselations.
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Jigsaw Maps
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
jigsaw maps - martin wattenberg
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
• Space-filling technique from Martin
Wattenberg - a mathematical experiment at
trying to achieve a “perfect” layout.
• Uses the mathematics of space-filling curves.
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Icicle Trees
• Edges implied by adjacency and spatial
relationship.
icicle tree in the infovis
toolkit - jean-daniel fekete
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Sunburst Diagrams
• Radial version of icicle trees.
sunburst diagram - john stasko
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Cascaded Lists
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
• Display one selected group of silbings at a time
• Mac OS X File System Browser
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More advanced trees…
• We can augment the approaches we’ve seen
so far with additional visualization and
interaction techniques. Some examples:
• Degree-of-Interest Trees / SpaceTree
– top-down node-link diagrams with focus+context
• Elastic Hierarchies
– node-link diagrams crossed with treemaps
• Dual Trees
– bi-directional top-down node-link diagrams
– developed for genealogical graphs
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degree-of-interest trees
doitrees - heer, card
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elastic hierarchies
• hybrid of nodelink diagrams
and treemaps
elastic hierarchies - zhao, mcguffin, chignell
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dual-trees
• a bidirectional tree
visualization
designed for
navigating
genealogical graphs
(family “trees”)
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
dual-trees - mcguffin, balakrishnan
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So what technique to use?
• A cautionary tale:
– CHI Browse-off and evaluation of the hyperbolic tree
– What makes the difference: the car or the driver?
• Reading
– People read faster by scanning in lines (not arcs!)
• Convention
– Does your application domain have established
conventions? How can you leverage or augment
those?
• Designs with multiple visual components
– How much screen real-estate do you give the tree?
– (Sometimes that indented tree works the best!)
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Design Exercise
• Brainstorm new visualizations for family “trees”
• Choose an aspect *NOT* covered by current designs
• Here are some of the complications to consider:
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People as individuals / Couples as reproductive units
Ordering by Generation vs. Time
Divorce/Death/Remarriage
Polygamy
Incest (!)
Social vs. Biological lineages?
• Think of important questions a visualization should answer,
use them to motivate the design
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Are two people related? In how many ways?
• Work in groups of 3 or more. You will be asked to briefly
present your ideas to the class on Monday!
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