ChartSeries.getClusterValues Method
        
 Gets the values used to position the specified grouping within a cluster of series at each value along the X axis.
 
         
        Parameters
        
            - groupingIndex
            
 
            - 
                
Type: Number (Integer)
(optional) The index of the grouping of points within this instance, optional unless groupingSource is set.
Optional: True 
        
        Return Value
        
Type: Array
        
ElementType: Object
        
An array of values used to uniquely identify the position for the grouping.