Hi underlid,

Please take a look at the example here: http://help.infragistics.com/NetAdvantage/WPF/2013.1/CLR4.0/?page=xamDataChart_Category_Stacked_Bar_Series.html

The XamDataChart works best when given a flat list of objects so AnonymousTypes should work however two dimensional arrays will not.  Dynamically adding new categories is definitely possible as this just involves adding a new data point for the new category and letting the change notifications fire to update the chart.  One thing to keep in mind with a stacked series though is that each data point needs to have the value for each stack already defined.  For example, if you open the above link you will see a StackedBarSeries.  The data source for this series has 6 data points and each data point has properties for each of the stacks. 

public class EnergyProduction
{
    public string Country { get; set; }
    public double Nuclear { get; set; }
    public double Coal { get; set; }
    public double Oil { get; set; }
    public double Gas { get; set; }
    public double Hydro { get; set; }
}

The Country property is the category and this is what appears on the Y Axis.  The other properties in this object represent each stack block for this data point.  The main thing here is that each data point needs the same amount of properties because the chart is going to create a StackFragmentSeries for each value property.  So while dynamically adding categories is possible, it is not possible to dynamically add stacks to an individual category.

Let me know if this doesn't make sense and I can try explaining it differently.

This posting helped me along: http://es.infragistics.com/community/forums/t/64311.aspx