wpf-devexpress-dot-xpf-dot-charts-dot-inumericmeasureunitscalculator-dot-calculatemeasureunit-x28-ienumerable-series-double-int32-double-double-double-double-x29.md
Calculates the numeric measurement unit that an axis should use for display.
Namespace : DevExpress.Xpf.Charts
Assembly : DevExpress.Xpf.Charts.v25.2.dll
NuGet Package : DevExpress.Wpf.Charts
double CalculateMeasureUnit(
IEnumerable<Series> series,
double axisLength,
int pixelsPerUnit,
double visualMin,
double visualMax,
double wholeMin,
double wholeMax
)
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 Double
| Name | Type | Description |
|---|---|---|
| series | IEnumerable<Series> |
All Series associated with the axis.
| | axisLength | Double |
The length of the axis’s current visual range in pixels.
| | pixelsPerUnit | Int32 |
The minimum count of pixels that series require to draw their points correctly.
| | visualMin | Double |
The visual range’s minimum value.
| | visualMax | Double |
The visual range’s maximum value.
| | wholeMin | Double |
The whole range’s minimum value.
| | wholeMax | Double |
The whole range’s maximum value.
|
| Type | Description |
|---|---|
| Double |
The calculated measurement unit.
|
For example, bars can overlap each other if the calculated measurement unit covers fewer pixels on the axis than the pixelPerUnit parameter specifies.
The automatic numeric 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. Design a class that implements the INumericMeasureUnitsCalculator interface and assign it to the AutomaticNumericScaleOptions.AutomaticMeasureUnitsCalculator property to use a custom measurement units calculation algorithm:
public class CustomAutomaticNumericMeasureUnitsCalculator : INumericMeasureUnitsCalculator {
public double CalculateMeasureUnit(
IEnumerable<Series> series,
double axisLength, int pixelsPerUnit,
double visualMin, double visualMax,
double wholeMin, double wholeMax
) {
double rawMeasureUnit = (visualMax - visualMin) * pixelsPerUnit / axisLength;
return Math.Pow(10, GetDigitCount((int)Math.Abs(rawMeasureUnit)));
}
private static readonly int[] valueStops = {
9, 99, 999, 9999, 99999, 999999, 9999999,
99999999, 999999999, Int32.MaxValue
};
private static int GetDigitCount(int value) {
for (int i = 0; ; i++)
if (value <= valueStops[i])
return i + 1;
}
}
Class CustomAutomaticNumericMeasureUnitsCalculator
Implements INumericMeasureUnitsCalculator
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 Double Implements INumericMeasureUnitsCalculator.CalculateMeasureUnit
Dim rawMeasureUnit = (visualMax - visualMin) * pixelsPerUnit / axisLength
Return Math.Pow(10, GetDigitCount(CType(Math.Abs(rawMeasureUnit), Integer)))
End Function
Private Shared ReadOnly valueStops As Integer() = {
9, 99, 999, 9999, 99999, 999999, 9999999,
99999999, 999999999, Int32.MaxValue
}
Private Shared Function GetDigitCount(value As Integer) As Integer
For i As Integer = 0 To valueStops.Length
If (value <= valueStops(i)) Then Return i + 1
Next
End Function
End Class
<dxc:ChartControl>
<dxc:XYDiagram2D>
<dxc:XYDiagram2D.AxisX>
<dxc:AxisX2D>
<dxc:AxisX2D.NumericScaleOptions>
<dxc:AutomaticNumericScaleOptions>
<dxc:AutomaticNumericScaleOptions.AutomaticMeasureUnitsCalculator>
<view:CustomAutomaticNumericMeasureUnitsCalculator/>
</dxc:AutomaticNumericScaleOptions.AutomaticMeasureUnitsCalculator>
</dxc:AutomaticNumericScaleOptions>
</dxc:AxisX2D.NumericScaleOptions>
</dxc:AxisX2D>
</dxc:XYDiagram2D.AxisX>
</dxc:XYDiagram2D>
</dxc:ChartControl>
See Also
INumericMeasureUnitsCalculator Interface