HorizonVis

Interactive Visual Exploration of Multivariate Medical Measurements in Diabetes Care

Lead / Contact	Wolfgang Aigner
Team	Wolfgang Aigner, Vienna University of Technology Michael Atanasov, HTBL Krems Alexander Rind, Vienna University of Technology Philipp Schindler, HTBL Krems Reinhardt Wenzina, HTBL Krems
Partners	Vienna University of Technology, Institute of Software Technology & Interactive Systems HTBL Krems, Department of Information Technology
Duration	September 2010 – May 2011
Description	Multivariate, time-oriented data plays a central role in many domains such as medicine, finance, or environmental engineering. Information Visualization can be an instrument to make such vast datasets intuitively comprehensible. As the number of time series increases, visualizations need to be space-efficient. Horizon graphs [Reijner, 2008] are an innovative approach to reduce required space by dividing the a chart into bands and layering these. While a first evaluation [Heer, et al., 2009] shows promising results, there is still room for optimization, especially regarding interaction techniques. In the project HorizonVis, we implemented the horizon graph as component for the VisuExplore framework. HorizonVis was tested with the diabetes dataset from the UCI Machine Learning Repository. In order to support flexible usage, it provides several customization settings: indexing values relative to a specific indexing point versus absolute values number of bands [Heer, et al., 2009] spread of a band, base value mirroring versus offset for values below the base value [Heer, et al., 2009] linear interpolation versus step chart different color schemes showing a legend [Saito et al., 2005] Future work includes evaluation of HorizonVis in application scenarios (e.g., diabetes care). The applicability of indexing is of special interest. Furthermore, we plan to extend HorizonVis with advanced interaction techniques.
Images	To retrieve an enlarged version of the images, click on them:
	HorizonVis with four variables compared to a line plot of the same variables and separate line plots	Customizing HorizonVis: (1) Indexing, (2) absolute values, (3) offset instead of mirroring, and (4) step chart mode
	Glucose readings of ten patients: Comparing (1) indexing versus (2) absolute values
	These three screenshots are licensed under a Creative Commons Attribution-NoDerivs 3.0 Unported License.
Related Work	VisuExplore – Gaining New Medical Insights from Visual Exploration MIDGAARD – Connecting Time-Oriented Data and Information to a Coherent Interactive Visualization TimeViewer – Visualizing Temporal Data using prefuse J. Heer, N. Kong, and M. Agrawala, Sizing the Horizon: The Effects of Chart Size and Layering on the Graphical Perception of Time Series Visualizations, in Proc. 27th Int. Conf. Human Factors in Computing Systems (CHI’09), Boston, MA, 2009, p. 1303–1312. H. Reijner, The Development of the Horizon Graph, in Electronic Proc. Vis08 Workshop From Theory to Practice: Design, Vision and Visualization, 2008. T. Saito, H.N. Miyamura, M. Yamamoto, H. Saito, Y. Hoshiya, and T. Kaseda, Two-Tone Pseudo Coloring: Compact Visualization for One-Dimensional Data, in Proc. IEEE Symp. Information Visualization (InfoVis 2005), 2005, p. 173–180.
Funding	This project was funded by the Sparkling Science initiative of the Federal Ministry of Science and Research. HorizonVis was awarded € 5000 for a top 5 submissions to the third call.
Alternative Webpages	official project description (in German)