What is a Sunburst Chart

Sunburst charts display hierarchies in a circular manner, with a sparse Nested Doughnut Chart.

The most inner circle contains all categories at the top level, from the first top series, displayed each with a different color. Then each other nested doughnut shows subcategories within each category, with the same color. Empty spaces or slices occur for NULL subcategory entries. Slices may vary in size when a measured value is attached to each entry.

Three recognizable types of layout are specific to a Sunburst Chart:

  1. Sunburst Pie Chart – with no missing slices, when subcategories have all values.
  2. Sparse Sunburst Chart – with some missing slices, opposite of a Sunburst Pie layout.
  3. Variable Size Sunburst Chart – when slices vary in size, according to another value.

Steps to Create a Sunburst Chart

Start Visual Xtractor or Data Xtractor. Connect to a database. Create or design a SQL query. Run the query and check the results.

  1. Display and enable the Chart query builder.
  2. Select one first category column as Radial ChartsSunburst, for the most inner circle.
  3. Select nested subcategory columns as Sunburst, for the other nested doughnuts.
  4. Select also eventually a numeric Size, to create variable size slices.

Sunburst Pie Chart

First Sunburst series is never sparse – i.e. with NULL values – and leads to the differently colored top categories from the most inner circle. The second Sunburst series returns subcategories, with the same color as their parent categories from the most inner circle. It just happens there is no NULL subcategory value, and this makes the chart look like a full Pie, with no missing slices.

Sunburst Pie Chart

Sparse Sunburst Chart

We add now a thirst Sunburst series to the previous chart. But this happens to have some NULL values, which will translate into some missing or empty slices on the outer circle. All slices on this last circle shows the same colors at the most inner circle, and this rule will not change for any other added series.

Sparse Sunburst Chart

Variable Size Sunburst Chart

A numeric Size selection added to a Sunburst chart leads to slices variable in size, according to these values. Compare, for instance, the top “Photography” entry with the same slice from the previous chart: here it is much smaller. This is because we no longer show doughnuts equally divided in slices, but variable in size.

Variable Size Sunburst Chart

Customize your Sunburst Chart

  1. Hide all data values, to avoid so much clutter.
  2. Show all nested doughnuts as thin rings or arcs.
  3. Change the drawing style and the semi-transparency.

Custom Sunburst Chart

Conclusion

  • Creating a Sunburst Chart in Data Xtractor or Visual Xtractor is fast and intuitive: set two or more nested category data columns as Sunburst, to see a circular hierarchy.
  • Add an optional numeric Size, to display variable size slices.
  • Empty spaces occur on NULL subcategories, on cell values left empty.
  • Switch to another builtin chart theme, or customize your own, for any possible color or other styles.