FlexChart / Working with FlexChart / FlexChart Elements / FlexChart Series / Error Bar
Error Bar

Error Bar series allows you to indicate variability of data or uncertainty in values. It enables you to display standard deviations and a range of error in variable data using error bars. Generally, results of scientific studies or experimental sciences use error bars in charts to depict variations in data from original values.

FlexChart lets you use Error Bar series in different chart types including Area, Column, Line, LineSymbols, Scatter, Spline, SplineArea, and SplineSymbols.

Error Bar series in FlexChart offers several features, as follows:

The following image displays Plus and Minus error amounts in the mean MCA (Middle Cerebral Artery) velocity data for different seizure types observed in children. 

The following code uses mean percentage values of MCA velocity during different kinds of seizures in children. The codes shows how to implement ErrorBar series in FlexChart.

Class DataCreator
    Public Shared Function CreateData() As List(Of DataItem)
        Dim data = New List(Of DataItem)()
        data.Add(New DataItem("Generalize", 15))
        data.Add(New DataItem("Unilateral Clonic", 22))
        data.Add(New DataItem("Subclinical", 20))
        data.Add(New DataItem("Tonic", 11))
        Return data
    End Function
End Class
Public Class DataItem
    Public Sub New(seizuretype__1 As String, meanmca__2 As Integer)
        SeizureType = seizuretype__1
        MeanMCA = meanmca__2
    End Sub

    Public Property SeizureType() As String
        Get
            Return m_SeizureType
        End Get
        Set
            m_SeizureType = Value
        End Set
    End Property
    Private m_SeizureType As String
    Public Property MeanMCA() As Integer
        Get
            Return m_MeanMCA
        End Get
        Set
            m_MeanMCA = Value
        End Set
    End Property
    Private m_MeanMCA As Integer
End Class
Partial Public Class MainPage
    Inherits Page
    Private _data As List(Of DataItem)
    Public Sub New()
        InitializeComponent()

        ' clear data series collection
        flexChart.Series.Clear()

        ' create ErrorBar series
        Dim errorBar As New C1.Xaml.Chart.ErrorBar()

        ' add the series to the data series collection
        flexChart.Series.Add(errorBar)

        ' bind X-axis and Y-axis
        flexChart.BindingX = "SeizureType"
        errorBar.Binding = "MeanMCA"

        ' specify error amount of the series
        errorBar.ErrorAmount = C1.Chart.ErrorAmount.Percentage

        ' specify the direction of the error
        errorBar.Direction = C1.Chart.ErrorBarDirection.Both

        ' specify the error value of the series
        errorBar.ErrorValue = 0.3

        ' style the ErrorBar series
        errorBar.EndStyle = C1.Chart.ErrorBarEndStyle.Cap
    End Sub
    Public ReadOnly Property Data() As List(Of DataItem)
        Get
            If _data Is Nothing Then
                _data = DataCreator.CreateData()
            End If

            Return _data
        End Get
    End Property
End Class