2 D FocusContext cs 5984 Information Visualization Chris

2 -D: Focus+Context cs 5984: Information Visualization Chris North

Strategies • • • Detail only: Zooming: Transparency: Overview+Detail: Focus+Context: detail without overview detail becomes overview detail on top of overview detail next to overview detail within overview • Focus+Context: • “Distortion-oriented display” • “Fisheye”

Wendy Schafer • Moosburg moosburg. cs. vt. edu

Document Lens • Robertson, “Document Lens”, p 562 • priya, parool

Bifocal Display • Leung, “Bifocal displays” • alex, qiang

Distortion Functions • Mapping from info surface to display surface f Information surface Display surface

Visual Transfer Functions Display surface Information surface Identity function = normal flat overview Information surface Bifocal

Magnification Functions Bifocal 1 st Derivative Magnification Information surface

Bifocal Display Disadvantage: 1 dimensional stretching on the 4 sides Bifocal

Perspective Wall / Document Lens Context gradually disappears Perspective

Non. Linear Magnification • • http: //www. cs. indiana. edu/hyplan/tkeahey/research/nlm. html http: //www. cs. indiana. edu/hyplan/tkeahey/research/papers/infovis. 98. html

“Bubble” Disadvantage: local context highly de-magnified Bubble

“Fisheye”, “wide-angle lens” Disadvantage: no flat area Wide-angle

Focus+Context • Bifocal • Perspective • Bubble • Wide-angle

Quiz: Table. Lens • Bifocal!

Fisheye Menus • combination of perspective

Calendar • Leung

Why not magnifying glass? • Hides local context

F+C • • • - distortion + smooth transition + more screen space efficient +easier layout - no flat overview, turn offf focus vs. O+D • - eye swapping • + higher zoom factor, higher scale • + really high scale with intermediates • + implementation (no math)

Next Week • Tues: Visual Overview Strategies • Stasko, “Information Mural” » ben, ahmed • Rayson, “Aggregate Towers” » anil, supriya • Thurs: Multiple View Strategies • Chi, “Visualization Spreadsheet” » mudita, abhi • North, “Snap-Together Visualization” » varun, kumar

Assignment • Homework 2 due today