1. Overview

A bubble chart, a good helper of data analysis and data visualization, is a variation of a scatter chart. The difference is that: the scatter chart plots grouped sets of X and Y values (2D) while a bubble chart plots grouped sets of X, Y and Z values (3D), where, Z values are used to define bubble sizes.

As shown below, use a bubble chart, a good reporting tool and business intelligence tool, to monitor the unit price, cost and the difference between inventory and ordering amount for each condiment:

2. Example

2.1 Prepare data

Create a new workbook and add dataset ds1 with SQL statement of select product name, cost price, unit price, (inventory-ordering amount) as difference between inventory and ordering amount from product where category ID = 2;

Query the unit price, cost and the difference between inventory and ordering amount of eachcondiment to make a piece of bubble chart that monitors the values of these three dimensions, where the bubble size is determined based on the difference between inventory and ordering amount.

2.2 Insert chart

Taking Float Chart as an example, click Insert > Float Element > Insert Chart
. Select Bubble Chart and click Ok.

2.3 Set chart data

The chart data is from dataset data. There are 3 fixed series in the bubble chart, indicating x axis, y axis and bubble size, as shown below:

Click Ok and the page-breaking preview effect is as shown below:

As shown, the default bubble chart is not so appealing. For example, it is unable to tell what each bubble represents and some bubbles are too small to be clearly seen. To fix this problem, we can adjust the Series Style of the bubble to make a delicate bubble chart.

2.4 Set series of bubble chart

Select Bubble Chart. Click Chart Property Table – Style > Series
, as shown below:

Size

The size of a bubble chart is divided into two types: area or width. The calculation unit is pixel.

The principle is to zoom out the bubble size to, for example, 50. In this way, the diameter of the maximum bubble in the bubble chart is 50 pixels. Then, based on selected size comparison method (e.g., bubble area), adjust the sizes of other bubbles based on the area percent of bubble.

Display

Display negative bubble: when Series 3 (z axis) contains negative values, if this option is checked,the negative bubble will be grayed; if this option is not checked, the negative bubble will not be displayed. As the above effect chart shown, paprika, tomato sauce and dried meat floss are grayed, indicating negative values.

Set Other Series

Settings of other series are same as the chart setting, like display tag, adding of warning line, etc.

2.5 Save and preview

Save template and click Page-breaking Preview to see the effect as shown above.

Click Bubble.cpt to check template effect online.
For completed templates, see:%FR_HOME%\WebReport\WEB-INF\reportlets\doc\Advanced\Chart\Bubble.cpt
.