The HeadAndShouldersAnnotation allows a user to draw a Head & Shoulders or Inverse Head & Shoulders chart pattern on a price chart. To create this annotation you have to set points at critical turning-points that will be connected by lines and polygons. Those points were limited by BasePointsCount (default value is 6).
The HeadAndShouldersAnnotation is a CompositeAnnotation (an annotation which consists of a number of other annotations) which consists of:
- LineAnnotations - which are connecting our points
- PolygonAnnotations - that are placed inside the triangles formed by the left/right shoulder and the head
- Text labels - which are TextAnnotations
Additional properties specific to HeadAndShouldersAnnotation include:
- Fill - defines the style for the polygon fils
Adding HeadAndShouldersAnnotations via mouse click
To add a HeadAndShouldersAnnotation via mouse click you have to add TradingAnnotationCreationModifier to your SciChartSurface.ChartModifier and set AnnotationType as HeadAndShouldersAnnotation. Please see the article on the TradingAnnotationCreationModifier for how to use this type.
Declaring a HeadAndShouldersAnnotation in XAML
To declare a HeadAndShouldersAnnotation in XAML you have to declare the annotation and then declare its InitialBasePoints collection that is actually collection of ComparablePoint objects. ComparablePoint stores X and Y values that are used for placing annotation point. InitialBasePoints collection is limited by BasePointsCount value. And default value is 7.
| Declaring a HeadAndShouldersAnnotation in XAML |
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<!-- XAxis, YAxis, RenderableSeries omitted for brevity --> <s:SciChartSurface.Annotations> <!--Declare HeadAndShouldersAnnotations--> <s:HeadAndShouldersAnnotation IsEditable="True"> <!-- Declare InitialBasePoints collection that is used for creating annotation from XAML. InitialBasePoints is actually observable collection of ComparablePoint-s. ComparablePoint stores X and Y point Value. --> <s:HeadAndShouldersAnnotation.InitialBasePoints> <!-- Placing first point --> <s:ComparablePoint X="0" Y="0"/> <!-- Placing second point --> <s:ComparablePoint X="2" Y="4"/> <!-- Placing third point --> <s:ComparablePoint X="4" Y="0"/> <!-- Placing fourth point --> <s:ComparablePoint X="8" Y="8"/> <!-- Placing fifth point --> <s:ComparablePoint X="12" Y="0"/> <!-- Placing sixth point --> <s:ComparablePoint X="14" Y="4"/> <!-- Placing seventh point --> <s:ComparablePoint X="16" Y="0"/> </s:HeadAndShouldersAnnotation.InitialBasePoints> </s:HeadAndShouldersAnnotation> </s:SciChartSurface.Annotations> |
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Please Note that the HeadAndShouldersAnnotation has limit of 7 base points. As you can see here, you just have to set this 7 points for the annotation: [X1=0; Y1=0], [X2=2; Y2=4], [X3=4; Y3=0], [X4=8; Y4=8], [X5=12; Y5=0], [X6=14; Y6=4] , [X7=16; Y7=0].
Declaring a HeadAndShouldersAnnotation in Code-Behind
To add a HeadAndShouldersAnnotation in code, simply use the following C# code:
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// Create a SciChartSurface. XAxis, YAxis omitted for brevity var sciChartSurface = new SciChartSurface(); // Create a HeadAndShouldersAnnotation. var headAndShoulder = new HeadAndShoulderAnnotation(); // HeadAndShouldersAnnotation should be added to //SciChartSurface.Annotation collection first, to make SetBasePoint() method //works correctly sciChart.Annotations.Add(headAndShoulder); // Set first point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(0, 0); // Set second point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(2, 4); // Set third point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(4, 0); // Set fourth point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(8, 8); // Set fifth point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(12, 0); // Set sixth point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(14, 4); // Set seventh point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(16, 0); |
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Declaring a HeadAndShouldersAnnotation in MVVM
To add an HeadAndShouldersAnnotation via MVVM please follow the instructions for adding annotations with MVVM: Declaring Annotations in MVVM with the AnnotationsBinding Markup Extension
To add a HeadAndShouldersAnnotation via a ViewModel you have to use SciChart markup extension called AnnotationsBinding,
| The AnnotationsBinding Markup Extension |
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<s:SciChartSurface Annotations="{s:AnnotationsBinding Annotations}"> </s:SciChartSurface> |
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Now you need to create collection for Annotations in ViewModel. Then create and add an HeadAndShouldersAnnotationViewModel to that collection of Annotations like this:
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public class MyViewModel : INotifyPropertyChanged { public ObservableCollection<IAnnotationViewModel> Annotations { get; } public void Foo() { // Create a HeadAndShouldersAnnotation. headAndShoulder = new HeadAndShouldersAnnotationViewModel(); // HeadAndShouldersAnnotation should be added to //SciChartSurface.Annotation collection first, to make SetBasePoint() method //works correctly Annotations.Add(headAndShoulder); // Set first point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(0, 0); // Set second point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(2, 4); // Set third point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(4, 0); // Set fourth point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(8, 8); // Set fifth point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(12, 0); // Set sixth point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(14, 4); // Set seventh point of HeadAndShouldersAnnotation headAndShoulder.SetBasePoint(16, 0); } } |
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