Radial Icicle Tree (RIT): Node Separation and Area Constancy.

Area of Science:

• Information Visualization
• Computer Graphics
• Human-Computer Interaction

Background:

• Icicle trees represent data using rectangles, but can suffer from unreadably narrow rectangles.
• Sunburst trees convert icicle rectangles to annular sectors, improving width but sacrificing size consistency across different tree depths.

Purpose of the Study:

• To introduce a novel visualization technique, the radial icicle tree (RIT), that addresses limitations of existing icicle and sunburst tree representations.
• To maintain faithful data-value-to-size mapping while improving the visibility of all nodes.

Main Methods:

• The radial icicle tree (RIT) transforms the bounding box of an icicle tree into circular, circular sector, or annular sector shapes.
• Introduced gaps between nodes to prevent visual merging of distinct subtrees.
• Ensured area constancy for nodes representing equal data values.

Main Results:

• The RIT visualization successfully transformed rectangular icicle trees into radial layouts.
• Analytical design and user-centered evaluations confirmed improvements over traditional icicle and sunburst trees.
• The RIT design maintained area constancy and improved node visibility without introducing new drawbacks.

Conclusions:

• The radial icicle tree (RIT) offers a superior alternative to icicle and sunburst trees for hierarchical data visualization.
• This new design effectively balances accurate size encoding with enhanced visual clarity.
• RIT provides a robust solution for representing tree structures with improved user perception.