A bivariate version of Andrews plots

A bivariate version of Andrews plots for naturally paired multivariate date is introduced. The bivariate Andrews plots are space curves, and are particularly effective for revealing patterns and clusters when depicted dynamically. Projections of the bivariate Andrews plots recover the familiar univariate Andrews plots. As an example, a series of experiments conducted to characterize the neurologic and morphologic consequences of acute cerebral artery occlusion in an animal (baboon) model and to evaluate the ability of antithrombotic therapy to reverse cerebral ischemia following acute thrombotic stroke is described. Bivariate Andrews plots of the paired latencies and amplitudes were drawn. It is shown that the dynamic display of the space curves provides an immediate means of visualizing similarities and differences, without invoking formal statistical tests.