A Decorated Parallel Coordinate Plot for Categorical Longitudinal Data

This article proposes a decorated parallel coordinate plot for longitudinal categorical data, featuring a jitter mechanism revealing the diversity of observed longitudinal patterns and allowing the tracking of each individual pattern, variable point and line widths reflecting weighted pattern frequencies, the rendering of simultaneous events, and different filter options for highlighting typical patterns. The proposed visual display has been developed for describing and exploring the order of event occurrences, but it can be equally applied to other types of longitudinal categorical data. Alongside the description of the principle of the plot, we demonstrate the scope of the plot with a real dataset. A second application and R code for the plot are available online as supplementary materials.