Display Series Error and Trend Indicators with DevExpress Presentation API

• Jun 01, 2026
• 4 minutes to read

The DevExpress Presentation API allows you to add series indicators to a Chart. You can use error bars to visualize data variability and a trend line to highlight direction in your data.

Supported Series Types

You can add error bars and a trend line to the following series:

• LineSeries
• BarSeries
• AreaSeries
• BubbleSeries
• ScatterSeries

Add Error Bars

Each series can have one vertical and one horizontal error bar instance.

Use the series ErrorBars property to access a series error bar collection. Add an ErrorBar object and configure its properties:

ErrorBar.Axis

Specifies the axis used to calculate error values. Available values include: Vertical, Horizontal, Both.

ErrorBar.Direction

Specifies the direction of error bars. Available values include: Plus, Minus, Both.

ErrorBar.Type

Specifies the type of error bars. Available values include: FixedValue, Percentage, StandardDeviation, StandardError, Custom. For error bars with custom error values (ErrorBar.Type is Custom), use the ErrorBar.Minus and ErrorBar.Plus properties to specify custom error values. These properties accept a IChartValueData objects (such as ChartDataReference or ChartNumericData).

ErrorBar.Value

Specifies the value of error bars.

The following code snippet adds vertical fixed-value error bars to a line series:

C#

using DevExpress.Docs.Office;
using DevExpress.Docs.Presentation;
using System.Drawing;

//...
Chart chart = new Chart();
chart.Width = presentation.SlideSize.Width;
chart.Height = presentation.SlideSize.Height;
slide.Shapes.Add(chart);

chart.Data[0, "A1"].TextValue = "Q1";
chart.Data[0, "A2"].TextValue = "Q2";
chart.Data[0, "A3"].TextValue = "Q3";
chart.Data[0, "B1"].NumericValue = 18;
chart.Data[0, "B2"].NumericValue = 24;
chart.Data[0, "B3"].NumericValue = 21;

LineSeries lineSeries = new LineSeries();
lineSeries.Arguments = new ChartDataReference(0, "A1", "A3");
lineSeries.Values = new ChartDataReference(0, "B1", "B3");
chart.Series.Add(lineSeries);

lineSeries.ErrorBars = new ErrorBarCollection {
        new ErrorBar {
            Axis = ErrorBarAxis.Vertical,
            Direction = ErrorBarDirection.Both,
            Type = ErrorValueType.FixedValue,
            Value = 1.5,
            ShowCap = true,
            OutlineStyle = new OutlineStyle { Fill = new SolidFill(Color.Magenta), Width = 8 }
        }
    };

VB.NET

Imports DevExpress.Docs.Office
Imports DevExpress.Docs.Presentation
Imports System.Drawing

'...
Dim chart As New Chart()
chart.Width = presentation.SlideSize.Width
chart.Height = presentation.SlideSize.Height
slide.Shapes.Add(chart)

chart.Data(0, "A1").TextValue = "Q1"
chart.Data(0, "A2").TextValue = "Q2"
chart.Data(0, "A3").TextValue = "Q3"
chart.Data(0, "B1").NumericValue = 18
chart.Data(0, "B2").NumericValue = 24
chart.Data(0, "B3").NumericValue = 21

Dim lineSeries As New LineSeries()
lineSeries.Arguments = New ChartDataReference(0, "A1", "A3")
lineSeries.Values = New ChartDataReference(0, "B1", "B3")
chart.Series.Add(lineSeries)

lineSeries.ErrorBars = New ErrorBarCollection() From {
    New ErrorBar() With {
        .Axis = ErrorBarAxis.Vertical,
        .Direction = ErrorBarDirection.Both,
        .Type = ErrorValueType.FixedValue,
        .Value = 1.5,
        .ShowCap = True,
        .OutlineStyle = New OutlineStyle() With {
            .Fill = New SolidFill(Color.Magenta),
            .Width = 8
        }
    }
}

Add a Trend Line

Use the TrendLine property to assign a TrendLine object to a series.

The following properties allow you to configure a trend line:

TrendLine.Type

Specifies the type of the trend line. Available values include: Linear, Exponential, Logarithmic, Polynomial, Power.

TrendLine.ShowEquationLabel

Specifies whether to display the equation formula of the trend line.

TrendLine.ShowRSquaredValue

Specifies whether to display the R-squared value of the trend line.

TrendLine.ForecastForward

Specifies the number of points to forecast forward.

TrendLine.ForecastBackward

Specifies the number of points to forecast backward.

The following code snippet adds a linear trend line and displays equation and R-squared values:

C#

using DevExpress.Docs.Office;
using DevExpress.Docs.Presentation;
using System.Drawing;

LineSeries lineSeries = new LineSeries();
lineSeries.Arguments = new ChartStringData(new[] { "Q1", "Q2", "Q3", "Q4", "Q5" });
lineSeries.Values = new ChartNumericData(new[] { 15d, 18d, 24d, 16d, 28d });
chart.Series.Add(lineSeries);

lineSeries.TrendLine = new TrendLine {
    Name = "Sales Trend",
    Type = TrendLineType.Linear,
    ShowEquationLabel = true,
    ShowRSquaredValue = true,
    ForecastForward = 1,
    EquationLabelOptions = new TrendLineLabel { TextProperties = new TextProperties { FontSize = 20, Bold = true } },
    OutlineStyle = new OutlineStyle { Fill = new SolidFill(Color.Magenta), Width = 4 }
};

VB.NET

Imports DevExpress.Docs.Office
Imports DevExpress.Docs.Presentation
Imports System.Drawing

Dim lineSeries As New LineSeries()
lineSeries.Arguments = New ChartStringData(New String() {"Q1", "Q2", "Q3", "Q4", "Q5"})
lineSeries.Values = New ChartNumericData(New Double() {15, 18, 24, 16, 28})
chart.Series.Add(lineSeries)

lineSeries.TrendLine = New TrendLine() With {
    .Name = "Sales Trend",
    .Type = TrendLineType.Linear,
    .ShowEquationLabel = True,
    .ShowRSquaredValue = True,
    .ForecastForward = 1,
    .EquationLabelOptions = New TrendLineLabel() With {
        .TextProperties = New TextProperties() With {
            .FontSize = 20,
            .Bold = True
        }
    },
    .OutlineStyle = New OutlineStyle() With {
        .Fill = New SolidFill(Color.Magenta),
        .Width = 4
    }
}