# Bubble Charts with FlexChart

## Content

Most chart types require that you provide a binding property to define the name of the property being charted. These types include Column, Bar, Scatter, Line, Area, and Spline.

A few chart types require additional information. For example, Bubble charts type requires an additional value to determine the bubble size.

In these cases, the __binding__ property should be set to a comma-delimited string containing the names of all the properties to be used for creating the chart. The data for this chart type can be defined using the __FlexChart__ or __Series binding__ property as a comma separated value in the following format: "yProperty, bubbleSizeProperty".

For example, the example below sets the __binding__ property of its series to 'expenses,downloads', so the expenses are used as Y values and downloads determine the bubble size:

```JavaScript
import * as chart from '@mescius/wijmo.chart';

// create the bubble chart
var myChart = new chart.FlexChart('#myChart', {
    itemsSource: getData(),
    chartType: 'Bubble',
    bindingX: 'sales',
    series: [
        { binding: 'expenses,downloads' }
    ]
});
```
![Bubble Chart](https://cdn.mescius.io/document-site-files/images/3c7113e2-10b3-45ed-8f3b-9fb1e0af2b74/chart/chart-bubble.png)

## Controlling the Min and Max Bubble Size
The variable bubble size is based upon the __binding__ field, however you can control the largest and smallest size the bubbles will render. The following options are supported:

* __bubble.maxSize__: Specifies the maximum size of symbols in the Bubble chart. The default value is 30 pixels.
* __bubble.minSize__: Specifies the minimum size of symbols in the Bubble chart. The default value is 5 pixels.

Example:

```JavaScript
myChart.options = {
  bubble: { 
      minSize: 5, 
      maxSize: 30 
      }
}
```