<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/10/15/changing-the-bar-width-ratio-on-a-flex-bar-chart/ -->
<mx:Application name="BarChart_barWidthRatio_test"
        xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">
 
    <mx:ArrayCollection id="arrColl">
        <mx:source>
            <mx:Array>
                <mx:Object name="R Winn" obp=".353" slg=".445" avg=".300" />
                <mx:Object name="P Feliz" obp=".290" slg=".418" avg=".253" />
                <mx:Object name="O Vizquel" obp=".305" slg=".316" avg=".246" />
                <mx:Object name="B Molina" obp=".298" slg=".433" avg=".276" />
                <mx:Object name="R Durham" obp=".295" slg=".343" avg=".218" />
            </mx:Array>
        </mx:source>
    </mx:ArrayCollection>
 
    <mx:ApplicationControlBar dock="true">
        <mx:Form>
            <mx:FormItem label="barWidthRatio:">
                <mx:HSlider id="slider"
                        minimum="0.0"
                        maximum="1.0"
                        value="0.6"
                        liveDragging="true"
                        tickInterval="0.1" />
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>
 
     <mx:BarChart id="barChart"
             showDataTips="true"
             dataProvider="{arrColl}"
             width="100%"
             height="100%">
        <mx:verticalAxis>
            <mx:CategoryAxis categoryField="name"/>
        </mx:verticalAxis>
        <mx:series>
            <mx:BarSeries id="barSeries"
                    yField="name"
                    xField="avg"
                    displayName="avg"
                    barWidthRatio="{slider.value}" />
        </mx:series>
    </mx:BarChart>
 
</mx:Application>