Trees 2

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Trees 2

• cs5984 Information Visualization
• Chris North

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2 Approaches

• Connection (node link)
• Containment (node in node)
• Structure vs. attributes
• Attributes only (multi-dimensional viz)
• Structure only (1 attribute, e.g. name)
• Structure attributes

A
C
B
A
B
C
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Containment Approach
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Treemaps (Shneiderman)

• Slice and Dice
• Alternate horizontal andvertical cuts for levels
• Node area ? node attribute
• Zoom onto nodes
• Space-Filling
• Structure 3 attributes
• Area, color, label

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Treemaps
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Treemaps
Balanced trees
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Treemaps

• 1000 nodes
• Quantitative attributes
• Good combination of structure attributes
• For unbalanced trees, structure more difficult
• Learning time 20 min
• Evaluation major performance boost over outliner
• Bad aspect ratios long narrow rectangles
• Large scale or deep causes solid black

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Treemap Algorithm

• Calculate sizes
• Recurse to children
• My size sum children sizes
• Draw Treemap (node, space, direction)
• Draw node rectangle in space
• Alternate direction
• For each child
• Calculate child space as of node space using
  size and direction
• Draw Treemap (child, child space, direction)

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Cushion Treemaps

• Van Wijk

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Squared Treemaps

• Wattenberg
• Van Wijk

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Treemaps on the Web

• Map of the Market http//www.smartmoney.com/mark
  etmap/
• People Map http//www.truepeers.com/
• Coffee Map http//www.peets.com/tast/11/coffee_s
  elector.asp

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DiskMapper

• http//www.miclog.com/dmdesc.htm

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Today

• Stasko, Sunburst, web
• Marcus, Marty

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Assignment

• Spring Break!
• Read for Tues (Mar 13)
• Beaudoin, Cheops, web
• Satya, Sumithra
• Furnas, Fisheye View, book pg 311

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Projects

• Data Structure Viz Tool
• Data Structure Viz Evaluation
• Biotech Viz
• Network Traffic Viz
• High-Dimensional Parameter Space Viz
• Chat Log Viz
• Web Snap
• List Viz / Menu UI
• Data Density and Distraction