AutomaticDateTimeScaleOptions.AutomaticMeasureUnitsCalculator Property

Gets or sets the automatic date-time measure unit calculator.

Namespace: DevExpress.Xpf.Charts

Assembly: DevExpress.Xpf.Charts.v24.1.dll

NuGet Package: DevExpress.Wpf.Charts

Declaration

C#

[Browsable(false)]
public IDateTimeMeasureUnitsCalculator AutomaticMeasureUnitsCalculator { get; set; }

VB.NET

<Browsable(False)>
Public Property AutomaticMeasureUnitsCalculator As IDateTimeMeasureUnitsCalculator

Property Value

Type	Description
IDateTimeMeasureUnitsCalculator	An object of the class implementing the IDateTimeMeasureUnitsCalculator interface.

Example

The automatic date-time scale options provide the capability to use a custom measurement unit calculator to determine the current measurement unit if the predefined one does not fit your requirements. Create a class that implements the IDateTimeMeasureUnitsCalculator interface and assign it to the AutomaticDateTimeScaleOptions.AutomaticMeasureUnitsCalculator property to use a custom measurement units calculation algorithm:

C#

public class CustomAutomaticDateTimeMeasureUnitsCalculator : IDateTimeMeasureUnitsCalculator {
    public DateTimeMeasureUnit CalculateMeasureUnit(
        IEnumerable<Series> series, 
        double axisLength, int pixelsPerUnit, 
        double visualMin, double visualMax, 
        double wholeMin, double wholeMax
    ) {
        double rawMeasureUnit = ((visualMax - visualMin) * pixelsPerUnit / axisLength);
        return PickDateTimeMeasureUnit(rawMeasureUnit);
    }

    static int[] unitMultipliers = {
        1, 1000, 60, 60, 24, 7, 4, 3, 4
    };
    static DateTimeMeasureUnit PickDateTimeMeasureUnit(double milliseconds) {
        double valueStop = 1.0;
        for (int i = 0; i < unitMultipliers.Length; i++) {
            valueStop *= unitMultipliers[i];
            if (milliseconds <= valueStop)
                return (DateTimeMeasureUnit)i;
        }
        return DateTimeMeasureUnit.Year;
    }
}

VB.NET

Public Class CustomAutomaticDateTimeMeasureUnitsCalculator
    Implements IDateTimeMeasureUnitsCalculator

    Public Function CalculateMeasureUnit(
            series As IEnumerable(Of Series),
            axisLength As Double, pixelsPerUnit As Integer,
            visualMin As Double, visualMax As Double,
            wholeMin As Double, wholeMax As Double
    ) As DateTimeMeasureUnit Implements IDateTimeMeasureUnitsCalculator.CalculateMeasureUnit
        Dim rawMeasureUnit As Double = ((visualMax - visualMin) _
                    * (pixelsPerUnit / axisLength))
        Return PickDateTimeMeasureUnit(rawMeasureUnit)
    End Function


    Private Shared unitMultipliers As Integer() = {1, 1000, 60, 60, 24, 7, 4, 3, 4}
    Private Shared Function PickDateTimeMeasureUnit(milliseconds As Double) As Double
        Dim valueStop As Double = 1.0
        For i As Integer = 0 To unitMultipliers.Length
            valueStop *= unitMultipliers(i)
            If (milliseconds <= valueStop) Then Return CType(i, DateTimeMeasureUnit)
        Next
        Return DateTimeMeasureUnit.Year
    End Function
End Class

XAML

<dxc:ChartControl>
    <dxc:XYDiagram2D>
        <dxc:XYDiagram2D.AxisX>
            <dxc:AxisX2D>
                <dxc:AxisX2D.DateTimeScaleOptions>
                    <dxc:AutomaticDateTimeScaleOptions>
                        <dxc:AutomaticDateTimeScaleOptions.AutomaticMeasureUnitsCalculator>
                            <view:CustomAutomaticDateTimeMeasureUnitsCalculator/>
                        </dxc:AutomaticDateTimeScaleOptions.AutomaticMeasureUnitsCalculator>
                    </dxc:AutomaticDateTimeScaleOptions>
                </dxc:AxisX2D.DateTimeScaleOptions>
            </dxc:AxisX2D>
        </dxc:XYDiagram2D.AxisX>
    </dxc:XYDiagram2D>
</dxc:ChartControl>