Evaluation of star coordinate boundaries

Abstract

In the visual analysis of high-dimensional data points, star coordinate plot maps the data points into an observable space by conducting a linear combination of radial distributed axes vectors. However, when plotting additional data points which are quite common in an engine performance and simulation model evaluation, the star coordinate is not effective due to undetermined plotting boundary. In response, we propose a geometric algorithm to determine the axis-aligned bounding box, minimum bounding box, and bounding polygon of the star coordinate with an evenly distributed configuration and an arbitrary distributed configuration respectively. These boundaries enable a continuous point rendering that adapts to the screen space boundary. Moreover, the determination of the boundaries provides deeper understandings on the star coordinate plots. Firstly, we amend the expression of the star coordinate by considering the boundaries such that the plotting can be generated reasonably. Secondly, the boundaries provide an objective and quantitative transformation to the widely accepted RadViz measures, in order to exploit the advantages of both. Finally, property analysis, such as the clumping effect of the star coordinate plot, is conducted based on the calculated boundaries.