Bubble charts are complex visualizations in which a large variety of data can be displayed at once. To create a bubble chart, we will need at least three data fields from the Measures category. Additionally, the fields from the Fields category can be used to assign colors and labels to the bubbles. In the bubble chart example below, each bubble represents an application object for which the technical and functional quality are displayed on the x- and y-axis. The size of bubbles represents the total costs of the application and the colors are the application's security levels. This bubble chart allows you to make choices for application rationalization and consolidation and can be configured by following the steps below.
1. In the example below, the starting configuration for a Chart is displayed. No data fields have been dragged into the columns and rows bar yet and no specific Chart type has been selected. Only the Chart option has been selected (in the red square below).
2. To select the bubble chart type, click the gears icon and select Chart Types....
3. In the pop-up window, the full range of available chart types is displayed. Select the Bubble chart and close the pop-up window.
4. Now that we have the right setup, we can start dragging data fields in the columns and rows bar. In the example below, three data fields from the Measure category (purple) have been dragged into the columns bar. The order of fields will determine which field is (from left to right) assigned to x-axis, y-axis and z-axis (bubble size).
The minimum requirements for creating a bubble chart have now been met and a visualization is displayed. However, to create more depth, we need additional fields.
5. In the example below, a data field from the Fields category has been added to the rows bar. The data field contains object titles. This creates the possibility to visualize a bubble for each object title. To achieve this, slide the data level bars to the right as shown below.
6. To add colors to the bubbles, we need one more field in the columns bar. Drag a field from the Fields category into the columns bar and slide the second data level bar to the right.