Treemapping

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TreeSize displaying a hard disks used space. Released as Public Domain by JAM-Software GmbH.
TreeSize displaying a hard disks used space. Released as Public Domain by JAM-Software GmbH.

Treemapping is a method for displaying tree-structured data using nested rectangles.

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[edit] History

In the early 1990s University of Maryland, College Park professor Ben Shneiderman, was plagued with chronic low disk space on the 80 MB server he was managing. He needed to find out how the space was being utilized; the largest files, and the users who were putting them there. Frustrated with the available tools that employed traditional tree structured node-link diagrams, Dr. Shneiderman conceived the Treemap.

Treemaps display rows of data as groups of rectangles that can be arranged, sized and colored to graphically reveal underlying data patterns. This visualization technique allows end users to easily recognize complicated data relationships that are otherwise non-obvious.

[edit] The Treemap algorithm

Two major factors drove the evolution and development of the Treemap algorithm: the aspect ratio and predictability of item placement, or order. It was noted early in the process that these properties have an inverse relationship. As the aspect ratio is optimized, the order of placement becomes less predictable. As the order becomes more stable, the aspect ratio is degraded.

To date, five primary treemap algorithms have been developed:

  • BinaryTree - Partially ordered, high aspect ratios, stable
  • Ordered - Partially ordered, medium aspect ratios, medium stability
  • SliceAndDice - Ordered, very high aspect ratios, stable
  • Squarified - Unordered, lowest aspect ratios, medium stability
  • Strip - Ordered, medium aspect ratios, medium stability

This can be explained more clearly soon.....

[edit] See also

[edit] External links

[edit] Examples

[edit] Academic descriptions

[edit] Open source

[edit] Commercial

  • Macrofocus Treemap An easy to use treemapping tool with some examples (Commercial).
  • Lab Escape's Heat Map Explorer available for the desktop, web or enterprise, or as a treemap SDK.
  • The Hive Group develops enterprise treemap software that is used by major corporations and government agencies.
  • ILOG JViews Charts, a commercial Java library with a thin client demo
  • ILOG Elixir, a commercial Flex library with a Flex/Flash demo
  • Cross-platform: AVS OpenViz offers commercial custom made Desktop, Enterprise, and Web enabled Treemap software
  • Incito offer enterprise and desktop Treemap products, that provide easy to use visual analysis tools.
  • MagnaView offers commercial desktop and enterprise visualization products, including a generalized version of treemaps.
  • TreeSize displays used hard disk space as Treemap.
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