Charting - How to remove line data points

Mar 28 at 4:35 AM
Edited Mar 28 at 4:41 AM
I have a Line Series chart with Line data points in it. how do i clear the old data points when i bind it new data.

my Code is
                            <chartingToolkit:Chart Name="LowCusumChart" >
                                <chartingToolkit:Chart.Resources>
                                    <Style x:Key="LCuRules" TargetType="{x:Type chartingToolkit:LineDataPoint}">
                                        <Setter Property="Template" >
                                            <Setter.Value>
                                                <ControlTemplate x:Name="LCTemplate" TargetType="{x:Type chartingToolkit:LineDataPoint}">
                                                    <Canvas x:Name="LNPlotArea" Margin="0,5,0,5" >
                                                        <Border BorderBrush="Purple" BorderThickness="2" Visibility="{Binding Path= CRules, Converter={StaticResource NullVisibility}}">
                                                            <Label  Foreground="Purple"  Content="{Binding Path=CRules}"  />
                                                        </Border>

                                                    </Canvas>
                                                </ControlTemplate>
                                            </Setter.Value>
                                        </Setter>
                                        <Setter Property="Background" Value="Black" />
                                    </Style>

                                </chartingToolkit:Chart.Resources>
                                <chartingToolkit:Chart.Series>                                      
                                    <chartingToolkit:LineSeries Name="LowCusumSeries" Title="Cusum" IndependentValueBinding="{Binding Path= EntryDate}" DependentValueBinding="{Binding Path=Cusum}"  >                                           
                                    </chartingToolkit:LineSeries>

public class CusumChart
{
    public string EntryDate { get; set; }
    public double? Cusum { get; set; }
    public string CRules { get; set; }.
    public bool CsrVisible { get; set; }

}