Graphics Reference
In-Depth Information
types of questions. For example, although each square is apparent, the
median for a group is not discernible. Sales (lower left) exhibits quite a
bit of variability, including some higher-income orange and even a bit of
green, whereas Construction (upper middle) tends to be largely purple. The
question of which group has the higher median income cannot be answered
by this treemap.
Instead, a hierarchical pie chart (sometimes referred to as a
sunburst
chart) can be effective for showing intermediate aggregations.
Figure 10-8
showsthesameoccupationincomedatasetwiththesamecolorscheme.The
outer perimeter shows the individual occupations (the
leaf nodes
), and
successive levels toward the center indicate successive summaries.
