Radar Charts!. Sheena Ellenburg. Outline. Overview Characteristics Nomenclature Usage Examples. Overview - Characteristics. 2-D 3 or more quantitative variables represented as axes starting from the same origin Equi -angular spokes called radii
Radar Charts! Sheena Ellenburg
Outline • Overview • Characteristics • Nomenclature • Usage • Examples
Overview - Characteristics • 2-D • 3 or more quantitative variablesrepresented as axes starting from the same origin • Equi-angular spokes called radii • Lines drawn between points to form a polygon • Relative position and angle of the axes generally not informative
Overview - Nomenclature • Also known as: • Web chart, cobweb chart (gridlines) • Spider chart (gridlines) • Star plot (no gridlines) • Irregular polygon • Polar chart (angular significance) • Kiviat chart (acceptable range bands) • Stardinates (Lanzenberger, 2003)
Usage • Ideal Data: • Multivariate (masque 3) • Many Quantitative to One Nominal • Sports players attributes, companies, coffee beans • Questions: • Which records/observations are most similar (clustering) • Which records/observations are dissimilar • Are there outliers?
When to Use a Radar Chart • If you can’t accommodate different quantitative scales in a bar graph • If the objective if to compare symmetry rather than magnitudes • Stephen Few’s resort example • Data fits circular display intuitively (counter/clockwise reading order is either explicitly obvious, or is unimportant) • Clocked data • Coffee bean taste attributes
“Stardinates” [Lanzenberger, 2003]: Lanzenberger, M., "The Stardinates - Visualizing Highly Structured Data", Proceedings of the Seventh International Conference on Information Visualization (IV'03), 2003.
Cupping Scores • SCAA Cupping Protocols • Sweet Marias Coffee Achives
How to Taste an Oyster • Tomato - The insider's guide to food and drink in Melbourne
European Sensory Network: Sensory Profiles of three German beers http://www.esn-network.com/635.html
More examples of food research • http://www.cjbio.net/html/innovation/food_application.asp • http://www.sciencedirect.com/science/article/pii/S0950329309000226
References • Kiviat Diagram: www2.cs.uidaho.edu • Polar Chart: advsofteng.com • Spider chart, star plot: wikipedia.org • Stardinates: infovis-wiki.net • Verghisgroup.com – 3 Things to Think About – A Warning Label for Radar Charts • Few, Stephen. Keep Radar Charts Below the Radar – Far Below. 2005. Perceptual Edge.