In This Topic
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:
- Error amount: Set up error bars on all data points using different ways, such as a fixed value, percentage, standard error, or standard deviation. In addition, it is possible to set a custom value to show a precise error amount, if required. To display error bars in any of these ways, set the ErrorAmount property from the ErrorAmount enumeration.
- Direction: Show error bars in the Plus, the Minus, or even both directions by setting the Direction property from the ErrorBarDirection enumeration.
- End style: Display error bars with or without caps by setting the EndStyle property from the ErrorBarEndStyle enumeration.
- Bar style: Customize the appearance of error bars using the ErrorBarStyle property.
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
class DataCreator
{
public static List<DataItem> CreateData()
{
var data = new List<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;
}
}
public class DataItem
{
public DataItem(string seizuretype, int meanmca)
{
SeizureType = seizuretype;
MeanMCA = meanmca;
}
public string SeizureType { get; set; }
public int MeanMCA { get; set; }
}
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
public sealed partial class MainPage : Page
{
private List<DataItem> _data;
public MainPage()
{
InitializeComponent();
// clear data series collection
flexChart.Series.Clear();
// create ErrorBar series
C1.Xaml.Chart.ErrorBar errorBar = 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 = .3;
// style the ErrorBar series
errorBar.EndStyle = C1.Chart.ErrorBarEndStyle.Cap;
}
public List<DataItem> Data
{
get
{
if (_data == null)
{
_data = DataCreator.CreateData();
}
return _data;
}
}
}