Documents for Excel, .NET Edition Documentation
Features / Chart / Customize Chart Objects / Series / Error Bars
In This Topic
    Error Bars
    In This Topic

    Error bars are used in charts to indicate the error or uncertainty of data. They act as an extremely useful tool for scientists, statisticians, and research analysts to showcase data variability and measurement accuracy.

    GcExcel allows you to configure error bars in charts using IErrorBar interface. The interface represents error bars in a chart series and provides properties to configure various types, end styles and value types of error bars. The error bars can also be exported or imported to JSON or a PDF document.

    Supported Chart Types

    The following chart types are supported while adding error bars in charts:

    Error Bar Types

    Type Snapshot Description
    Plus

    Error bar depicts only the positive values.

    C#
    Copy Code
    series.YErrorBar.Type = ErrorBarInclude.Plus;
    Minus

    Error bar depicts only the negative values.

    C#
    Copy Code
    series.YErrorBar.Type = ErrorBarInclude.Minus;
    Both

    Error bar depicts positive and negative values at the same time

    C#
    Copy Code
    series.YErrorBar.Type = ErrorBarInclude.Both;

    Error Bar End Styles

    Type Snapshot Description
    Cap

    Error bar displays caps at the end of error bar lines.

    C#
    Copy Code
    series.YErrorBar.EndStyle = EndStyleCap.Cap;
    No Cap

    Error bar does not display caps at the end of error bar lines.

    C#
    Copy Code
    series.YErrorBar.EndStyle = EndStyleCap.NoCap;

    Error Bar Value Types

    Type Snapshot Description
    Fixed Value

    Error bar represents the error as an absolute value.

    C#
    Copy Code
    series1.YErrorBar.ValueType = ErrorBarType.FixedValue;
    Percentage

    Error bar represents the error as a percentage of data value in the same direction axis.

    C#
    Copy Code
    series1.YErrorBar.ValueType = ErrorBarType.Percentage;
    Standard Deviation

    Error bar represents the error as a calculating value which depends on the set deviation and chart data values.

    C#
    Copy Code
    series1.YErrorBar.ValueType = ErrorBarType.StDev;
    Standard Error

    Error bar represents the error as a calculating value which only depends on the chart data values.

    C#
    Copy Code
    series1.YErrorBar.ValueType = ErrorBarType.StError;
    Custom

    Error bar represents the error values that are set with positive and negative values respectively by formulas or fixed values.

    C#
    Copy Code
    series1.YErrorBar.ValueType = ErrorBarType.Custom;

    Note: In Custom value type, the array and reference formula string for plus or minus is supported. The final count of error bar values is evaluated by the formula string (for example, "=Sheet1!$B$2:$D$2" or "={1,2,3}"). The error bar values are displayed based on the total count of values:
    If count = 1: all error bars have the same value.
    If count < number of data points: the value of rest of the error bars is zero.
    If count > number of data points: the remaining values will do nothing.

     

    Using Code


    Refer to the following example code to add error bars using various properties.

    C#
    Copy Code
        // Initialize workbook
        Workbook workbook = new Workbook();
        // Fetch default worksheet
        IWorksheet worksheet = workbook.Worksheets[0];
        // Prepare data for chart
        worksheet.Range["A1:D4"].Value = new object[,]
        {
    {null, "Q1", "Q2", "Q3"},
    {"Mobile Phones", 1330, 2345, 3493},
    {"Laptops", 2032, 3632, 2197},
    {"Tablets", 6233, 3270, 2030}
        };
        worksheet.Range["A:D"].Columns.AutoFit();
        // Add Column Chart
        IShape columnChartshape = worksheet.Shapes.AddChart(ChartType.ColumnClustered, 250, 20, 360, 230);
    
        // Adding series to SeriesCollection
        columnChartshape.Chart.SeriesCollection.Add(worksheet.Range["A1:D4"], RowCol.Columns, true, true);
    
        // Get first series
        ISeries series1 = columnChartshape.Chart.SeriesCollection[0];
    
        //Config first series' properties
        series1.HasErrorBars = true;
        series1.YErrorBar.Type = ErrorBarInclude.Both;
        series1.YErrorBar.ValueType = ErrorBarType.Custom;
        series1.YErrorBar.EndStyle = EndStyleCap.Cap;
        series1.YErrorBar.Plus = "={200,400,600}";
        series1.YErrorBar.Minus = "={600,400,200}";
    
        // Get second series
        ISeries series2 = columnChartshape.Chart.SeriesCollection[1];
    
        //Config second series' properties
        series2.HasErrorBars = true;
        series2.YErrorBar.Type = ErrorBarInclude.Plus;
        series2.YErrorBar.ValueType = ErrorBarType.FixedValue;
        series2.YErrorBar.EndStyle = EndStyleCap.Cap;
        series2.YErrorBar.Amount = 1000;
        series2.YErrorBar.Format.Line.Color.RGB = Color.Red;
        series2.YErrorBar.Format.Line.Weight = 2;
    
        // Get last series
        ISeries series3 = columnChartshape.Chart.SeriesCollection[2];
    
        //Config last series' properties
        series3.HasErrorBars = true;
        series3.YErrorBar.Type = ErrorBarInclude.Both;
        series3.YErrorBar.ValueType = ErrorBarType.StError;
        series3.YErrorBar.EndStyle = EndStyleCap.NoCap;
    
        //save to an excel file
        workbook.Save("ErrorBar.xlsx");

    Important Points

    Limitation

    There can be some difference between the exported PDF and Excel containing error bars. It is caused due to different ways of calculating error bar value between GcExcel and Excel.