This site describes an interactive visualization tool, SpiralGlyphics, for exploring cyclic multivariate data. Cyclic or periodic data arises predominantly from sampling a particular phenomena over time. Cyclic behavior is indicated by a repeated pattern (usually with some variation) of a particular length. Sources of cyclic data include the weather, the human body, agriculture, astronomy, oceanography, and the stock market. We study cyclic data to try to understand both intracycle and intercycle characteristics. Most graphical approaches to analyzing data for cyclic behavior simply plot the data along a single axis in time or space, relying on the observer's innate pattern recognition skills and short term memory to detect the repeated patterns. Our goal is to develop graphical tools which simplify the process of detecting cyclic patterns in data and help in the analysis of inter- and intracyclic behavior.
A multivariate data set is simply one which contains multiple dimensions or variables for each data point. For example, one might sample a patient's temperature, pulse, and blood pressure at regular intervals. Most spreadsheet tables can be considered to be multivariate data sets, as there are entries (rows) with multiple dimensions (columns). The challenge is to create a visual representation of each entry that conveys information about some or all of the variables. Existing visualization techniques for data sets which often contain cyclic behavior (time-series) have mostly focussed on univariate or bivariate sets. We are interested in exploring data sets with higher numbers of variables (3 to 10 or more).
SpiralGlyphics is an interactive Java application which supports the visual exploration of cyclic multivariate data sets using a variety of glyph types and layout strategies. It is curently implemented using JDK 1.1.7B. Applet and Java Plugin versions are available as well for testing the functionality (using fixed data sets). These are best viewed using Netscape version 4.5 or higher or Internet Explorer version 4.0 or higher. The Plugin version only works on architectures for which the Java Plugin is avaiable.
Click here for an overview of the functionality of SpiralGlyphics and here to examine some case studies.