If you are using a line chart, then the DataMapping doesn’t use ValueX and ValueY chart parameters, but rather Label for the X axis, and Value for the Y axis, because it’s treated as a “Single value chart”. So adjusting the Xaml to look like so should work:

<Window x:Class="WpfApplication3.Window1"

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

    Title="Window1" Height="300" Width="300"

        xmlns:my="http://infragistics.com/Chart">

    <Grid>

        <my:XamChart Name="ChartTimeseries" Grid.Row="1" Grid.Column="1" Width="Auto" Height="Auto" Margin="25" >

            <my:XamChart.Series>

                <my:Series

                      StrokeThickness="4"

                      ChartType="Line"

                      DataSource="{Binding TimeSeries, UpdateSourceTrigger=PropertyChanged}"

                      DataMapping="Label=ValueAsOf; Value=ValueAbsolute"

                      Fill="#FF6CA224" >

                </my:Series>

            </my:XamChart.Series>

            <my:XamChart.Axes>

                <my:Axis AxisType="PrimaryX" >

                    <my:Axis.Label>

                        <my:Label Format="{}{0}" />

                    </my:Axis.Label>

                </my:Axis>

                <my:Axis AxisType="PrimaryY">

                    <my:Axis.Label>

                        <my:Label Angle="-45" Format="{}{0:c}" />

                    </my:Axis.Label>

                </my:Axis>

            </my:XamChart.Axes>

        </my:XamChart>

    </Grid>

</Window>

And this is the code behind I used:

public partial class Window1 : Window

    {

        public Window1()

        {

            InitializeComponent();

            this.DataContext = new TimeSeriesViewModel();

        }

    }

    public class TimeSeriesViewModel

    {

        private ObservableCollection<TimeEntryViewModel> _timeSeries;

        public ObservableCollection<TimeEntryViewModel> TimeSeries

        {

            get

            {

                if (_timeSeries == null)

                {

                    _timeSeries = TestDataProvider.GetData();

                }

                return _timeSeries;

            }

        }

    }

    public class TimeEntryViewModel

    {

        public DateTime ValueAsOf { get; set; }

        public double ValueAbsolute { get; set; }

    }

    public class TestDataProvider

    {

        public static ObservableCollection<TimeEntryViewModel> GetData()

        {

            ObservableCollection<TimeEntryViewModel> list = new ObservableCollection<TimeEntryViewModel>();

            list.Add(new TimeEntryViewModel() { ValueAsOf = new DateTime(2009, 1, 1), ValueAbsolute = 11 });

            list.Add(new TimeEntryViewModel() { ValueAsOf = new DateTime(2009, 2, 1), ValueAbsolute = 10 });

            list.Add(new TimeEntryViewModel() { ValueAsOf = new DateTime(2009, 3, 1), ValueAbsolute = 10 });

            list.Add(new TimeEntryViewModel() { ValueAsOf = new DateTime(2009, 4, 1), ValueAbsolute = 9 });

            list.Add(new TimeEntryViewModel() { ValueAsOf = new DateTime(2009, 5, 1), ValueAbsolute = 11 });

            list.Add(new TimeEntryViewModel() { ValueAsOf = new DateTime(2009, 6, 1), ValueAbsolute = 10 });

            list.Add(new TimeEntryViewModel() { ValueAsOf = new DateTime(2009, 7, 1), ValueAbsolute = 12 });

            return list;

        }

    }