The ring chart is a circular chart, very similar to a pie chart that is divided into sections, illustrating the relative disk space occupied by each of a folder’s subfolders. The arc length of each section is proportional to the space occupied by the entire folder. It is named for its resemblance to a ring and is also referred to as a donut chart.
Each section of the ring chart is painted with a random color, and to the extent possible, a label is displayed for each section. When the ring chart consists of many sections some labels are eliminated to maintain legibility of the chart. When the mouse cursor is moved over a portion of the ring a tooltip is displayed for that section.
The size data view displays a modified ring chart that contains concentric rings to depict sub-folders of each folder (see figure 2). The ring chart in the size data view also allows for “drilling down” to subfolders. The drilldown capability is indicate by a finger cursor. The finger cursor is displayed when the mouse is positioned over any subdirectory of the currently displayed directory, and a single click will “drill down” and update the display to the directory under the mouse.