Eager Eyes: Visuelle Kommunikation in Kunst und Computergrafik Visualisierung Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Roots of InfoVis • Based on – Statistical diagrams – Information Graphics – Isotype, Otto Neurath Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Data Sets • Unstructured Data – Data Table • Rows: Data Samples/Points • Columns: Attributes/Dimensions • Structured Data – Trees (e.g., file system, organizational chart, …) – Graphs (telephone connections, …) Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Scatterplot • Two data axis on plane • One point per data sample • Find – Accumulation – Trends – Correlations • How many points in one location? Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Scatterplot Matrix • Matrix arrangement • n*(n-1)/2 plots for n dimensions • Often histograms on main diagonal • Good overview, little detail Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Spiral for Temporal Data • Data about sick leave in German state over one year • Number of days per revolution • Pattern obvious when correct number of days Robert Kosara Visuelle Kommunikation in Kunst und CompSuctheurgmrafnikn et al http://www.eagereyes.org/LVA/ Temporal Data in ICU • Show data on monitors • Good – Red/blue, round • Bad – Purple, crumpled • Good overview of patient status Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Glyphs • Objects whose features represent data – Length – Angle – Color – Shape, etc. • Often based on metaphors • Different from icons – Icons are signals, glyphs show data Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Glyphs • Objects whose features represent data – Length – Angle – Color – Shape, etc. • Often based on metaphors • Different from icons – Icons are signals, glyphs show data Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Glyphs/Stick Figures • Glyphs consisting only of lines • Data encoded in lengths and angles • Very effective with large numbers Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ VIE-VISU • Glyph for showing ICU data Horn, Popow, Unterasinger Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Glyphs Over Time Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Star Plot/Glyph http://www.isr.yorku.ca/ http://www.togaware.com/ Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Chernoff Faces • Glyph shaped like face • Up to 25 variables – Shape of head, nose, etc. – Width/height of nose – Mouth size/shape – Etc • Difficult to read • Priorities of features • Suggested in jest? (Grinstein) Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Glyphs • Advantages – Easy to tell multidimensional differences – Find complex patterns in time series data – Can be based on metaphor • Disadvantages – Individual values hard to read – Require legend – Limited number of dimensions – Dimensions/directions not equal Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Parallel Coordinates • Coordinate axes parallel instead of orthogonal • Used in Statistics • InfoVis adds interaction, large data sets • Alfred Inselberg, 1987 Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Example Parallel Coordinates Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Brushing and Parallel Coordinates • Brushing: Coloring of Data Points • Left years 1970-72, right 1980-82 • Changes in weight, mileage, cylinders Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Data Types • Quantitative: – Ratio: ratios are equivalent, e.g., body weight, age, weight, … – Interval: meaningful differences, e.g., dates, years, temperature, … • Qualitative: – Ordinal: natural ordering, e.g., school grades – Nominal: e.g., gender Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Categorical Data • Difficult to display – Bad use of screen space – Assign locations to unordered/non-spaced values? • Many overlapping samples • No correlations visible Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Mosaic Plots • Number of objects, not individual data points • Stacked dimensions • Hard to read for more than two dimensions Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Parallel Sets • Recent work (InfoVis 2005, TVCG 2006) • Idea based on parallel coordinates and mosaic plots • Displays sets instead of samples Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Parallel Sets: Titanic Dataset 5 0 0 2 r e s u a H , a r a s o K , x i d n e B Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Survival by Class Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Survival Relative to Class Size • (Multiple) Correspondence Analysis Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Maps • Pre-date written language (Stone Age) • Abstracted representation of space • Different maps for different purposes • Example: route maps 0 0 0 2 H P A R G G I S , e t l o t S , a l a w a r g A Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Maps • Special symbol language • Many layers of information • Labels • Accurate distances/angles • Map-based visualizations/ illustrations Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Subway Map, geographical Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Subway Map, topological Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Subway Maps • “Non-realistic”, do not represent space • Show connections, relations • Only 45° angles • Harry Beck designed London tube map (1933), based on circuit diagrams Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Minard, Napoleon’s March • Napoleon’s March to Moscow, 1812-13 Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Route Maps • Represent more detail where necessary – Start/end of journey, when in city • Less detail along way, e.g., highway • Distorted lengths, additional info at intersections 0 0 0 2 H P A R G G I S , e t l o t S , a l a w a r g A Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Scientific vs. InfoVis Direct Volume Parallel Rendering Coordinates [Hauser et al., Vis 2000] [Fua et al., Vis 1999] Isosurfaces Glyphs Scatter Plots Line Integral [http://www.axon.com/ Convolution gn_Acuity.html] [Cabral & Leedom, Node-link SIGGRAPH 1993] Streamlines Diagrams [Lamping et al., CHI 1995] [Verma et al., Vis 2000] Continuous Discrete Data Data Tory & Möller, 2004 Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Scientific vs. InfoVis Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Structured Data: Trees • Hierarchical Data Structure • Each node has – One parent (except root) – 0-n children • Examples – Command structures – Directory trees – Genealogical trees Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Cone Trees, Cam Trees • Arrange child nodes in circle • Move selected node forward with animation • Cam trees horizontal for better labels Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Treemaps • Space-filling visualization of hierarchy • Divide space in x and y directions, according to node size • Labels on nodes • Problem: Nodes with different aspect ratios hard to compare Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Squarified Treemaps • Make nodes as square as possible – Easier to compare – Harder to judge overall size • Optimization process http://www.codeproject.com/csharp/treemaps.asp Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Cushion Treemaps • Squarified Treemaps • Pseudo-3D look • Fewer lines, less clutter, fewer high spatial frequencies Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Botanical Visualization • Tree visualization that looks like tree • Files are conical “fruits” • Efficient use of space • Combination of branching points • Limited use for visualization Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Treemap for Financial Data • Hierarchical map of stock market • Squarified treemaps • Color shows trend • Layout stable over time www.smartmoney.com Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Example: Map of the Market • The market shortly after Hurricane Katrina Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ Hyperbolic Trees • Node-link diagram in half sphere • Nodes near center get more space • Move nodes around for navigation • Loose orientation easily Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/ SpaceTree • Highly interactive tree visualization • Shows details on demand • Context information – Presence and size of subtrees • Compared to hyperbolic tree, Explorer, etc. Plaisant et al, InfoVis 2002 Robert Kosara Visuelle Kommunikation in Kunst und Computergrafik http://www.eagereyes.org/LVA/.