Flex BubbleChart - make bubble size relative to size of chart?

I'm wondering if there is any way to make the bubble sizes scale or resize when the size of the chart resizes. If the bubbles are set to a specific pixel size, it seems as though the size is set and that's it. So, if your chart is large, the bubble is size X and if the chart is small the bubble is still size X.

Here's a sample app to show you what I mean. Any help or ideas would be appreciated?

Thanks!

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
    <mx:Script>
        <![CDATA[
            import mx.collections.ArrayCollection;
            [Bindable]
            private var s1:ArrayCollection = new ArrayCollection( [
                {"x": 20, "y": 10, "r":10 },
                {"x": 40, "y": 5, "r":20 } ,
                {"x": 60, "y": 0, "r":30 }]);
    ]]>
    </mx:Script>

    <!-- Define custom color and line style for the bubbles. -->
    <mx:SolidColor id="sc1" color="red" alpha=".7"/>
    <mx:Stroke id="stroke1" color="red" weight="2"/>

    <mx:BubbleChart id="myChart" showDataTips="true" height="100%" width="开发者_开发知识库100%"> 
        <mx:series>
            <mx:BubbleSeries 
                dataProvider="{s1}" 
                displayName="series1" 
                xField="x" 
                yField="y" 
                radiusField="r"
                selectable="true"
                fill="{sc1}"
                stroke="{stroke1}"
            />
        </mx:series>   
    </mx:BubbleChart>

</mx:Application>

---

What you can do is , add a resize event to your application.

<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" resize="handleMainWindowResize()">

In script part of the programme declare the function and in that function change the properties of the BubbleSeries:

<mx:Script>
        <![CDATA[
public function handleMainWindowResize():void
{
  //change values of s1 according to the percentage increase (this is important)
            for each(series in myChart.series)
            {
                var bubbleSeries:BubbleSeries= series as BubbleSeries;
                bubbleSeries.dataProvider =s1;//Resetting the data provider with the changed values

            }
}
    ]]>

</mx:Script>

Or you can always use scaling transformations. But the above is the right way to go through it.