Redraw a chart with new or updated data by using the <apex:actionSupport> component,
or by using JavaScript remoting and your own JavaScript code.
<apex:actionSupport> allows you to update the chart using only Visualforce. JavaScript remoting requires you to write some JavaScript code, but provides more
flexibility and smoother transitions.
Refreshing Chart Data Using <apex:actionSupport>
Update a Visualforce chart in response to a user’s actions by adding the <apex:actionSupport> component to Visualforce user interface elements that affect the chart’s data.
Refreshing Chart Data Using JavaScript Remoting
Update a Visualforce chart periodically, or in response to a user’s actions, using custom JavaScript. JavaScript code can respond to complex user activity or timer events, and use JavaScript remoting to retrieve new chart data whenever required.