Programmatically Update a Chart object

I have a workbook where I have to carefully control calculation activity to only those cells and objects that need to be updated. I have a chart located on sheet1 that needs to be updated. My approach is

Dim Cht as Object
Set Cht = ActiveChart
Cht.Calculate

This generates an error. What is the preferred code here?
Thanks in advance for any assistance

Charts always reflect the source cells. Calculation mode does not apply to them.

Sub snb()
 Sheets(1).ChartObjects(1).Chart.Refresh
End Sub

SNB,

This solved my problem. Thanks

Steve