軸交差の構成

<ig:CategoryXAxis x:Name="xAxis"
                  StrokeThickness="5"
                  Stroke="Red"
                  CrossingValue="20"
                  LabelLocation="InsideBottom"
                  CrossingAxis="{x:Reference yAxis}"
                  ItemsSource="{StaticResource DataSource}"
                  Label="Label">
</ig:CategoryXAxis>
<ig:NumericYAxis x:Name="yAxis"
                 StrokeThickness="5"
                 Stroke="Green"
                 CrossingValue="100"
                 LabelLocation="InsideLeft"
                 CrossingAxis="{x:Reference xAxis}">
</ig:NumericYAxis>

var yAxis = new NumericYAxis()
{
    StrokeThickness = 5,
    Stroke = new SolidColorBrush(Color.Green),
    CrossingValue = 100,
    LabelLocation = AxisLabelsLocation.InsideLeft
};
var xAxis = new CategoryXAxis()
{
    StrokeThickness = 5,
    Stroke = new SolidColorBrush(Color.Red),
    ItemsSource = data,
    Label = "Label",
    CrossingValue = 20,
    LabelLocation = AxisLabelsLocation.InsideBottom
};
xAxis.CrossingAxis = yAxis;
yAxis.CrossingAxis = xAxis;