Visualization of multidimensional data using modifications of the Grand Tour

Current implementations of Asimov's Grand Tour (for example in XLISP-STAT by Tierney, 1990, or in XGobi by Buja et al., 1996) do not remember the path of projections and show only the current state during the touring process. We propose a modification of the Grand Tour, named Tracking Grand Tour (TGT), that shows the trace of the touring process as small 'comet trails' of the projected points. The usefulness of the TGT is demonstrated with a simulated and a real data set.