Captions

Figure 1: Shell plot visualizing the binned count of cancer cells in the blood of 164 anonymized subjects during treatment. Total observation period ranged from a few days to more than 8 years. Hover of the episode sectors to reveal additional information of the episode and linked observation and subject. Click on an episode to copy the data row to the clipboard. Scroll to zoom in and out. Figure 2: Terminology used for the shell plot. Figure 3: Parameterization of the layout for the shell plot. The circled numbers indicate the order in which to calculate the (derived) parameters. See text for more details. Figure 4: Process diagram for the shell plot. Only one input is truly compulsory and that is the observational data with the features Subject, Start, End, and Group. Although Width and Height are strictly layout parameters, they are treated as true input values because of their importance. id represents an unique HTML identifier to avoid conflict when working with more than one shell plot per HTML page. The input gridlines corresponds to the at argument of the axis() function. To allow extra information to be shown upon hover, an infobox template must be provided. Layout and styling information can be provided as a YAML configuration file. Additional and dynamic styling (e.g. highlighting of sector upon hover) is provided as CSS style sheets. Figure 5: Distribution of the total treatment time (expressed in days since admission) among all subjects. The layout in this plot is hindered by the longer observation period of Zakariya Tucker which makes other observation scale along. In many realistic cases, the distribution of observation periods is even more skewed and leptocurtic then in this dataset. Figure 6: Plotting the subject identifiers of the top 200 or 500 episodes on a canvas containing a number of guidelines. Figure 7: Because the plot is constructed as a SVG element, it consist purely of XML code allowing for all kinds of interactivity through CSS, Javascript and derivatives thereof. If you are viewing this in your browser, you can try and select some text in Figure 6. Figure 8: Drawing the upper arc of the highlighted observation in Figure 2 using an SVG <path> element. Figure 9: Drawing our first annulus sector. Figure 10: Hover over the sector to reveal the data attached. Mind that at this point no styling has been performed. Figure 11: Example legend. Figure 12: Test of drawing the gridlines (pink).