DxChartAggregationSettings Class

Contains data aggregation settings.

Assembly: DevExpress.Blazor.v23.2.dll

Declaration

public class DxChartAggregationSettings :
    DxSettingsComponent<ChartAggregationSettingsModel>

Remarks

The <DxChart> component can use different aggregate methods to group data and decrease the number of visible points. This feature allows you to optimize chart performance.

Data aggregation is available for the X-axis. The chart splits the X-axis into intervals, aggregates data for each interval and shows the result values as series points. When users zoom the chart, it re-aggregates data.

Data Aggregation

To enable aggregation, add a DxChartAggregationSettings object to the markup and set its Enabled property to true. To specify an aggregation method, use the Method property (the default method is Auto).

Index.razor
BagrainDataPoint.cs

<DxChart T="BargainDataPoint"
            Data="@UsdJpyData"
            @key="@Params.ThemeName"
            CssClass="w-100">
    <DxChartLegend Position="RelativePosition.Inside"
                    VerticalAlignment="VerticalEdge.Top"
                    HorizontalAlignment="HorizontalAlignment.Right" />
    <DxChartLineSeries T="BargainDataPoint"
                        TArgument="DateTime"
                        TValue="double"
                        ArgumentField="i => i.DateTimeStamp"
                        ValueField="i => i.Price"
                        Name="USDJPY">
        <DxChartSeriesPoint Visible="false" />
        <DxChartAggregationSettings Enabled="true" 
                                    Method="ChartAggregationMethod.Average" />
    </DxChartLineSeries>
    <DxChartArgumentAxis>
        <DxChartAxisRange StartValue="new DateTime(2020, 01, 01)"
                            EndValue="new DateTime(2021, 01, 29)" />
    </DxChartArgumentAxis>
    <DxChartZoomAndPanSettings ArgumentAxisZoomAndPanMode="ChartAxisZoomAndPanMode.Both" />
    <DxChartScrollBarSettings ArgumentAxisScrollBarVisible="true" 
                                ArgumentAxisScrollBarPosition="ChartScrollBarPosition.Bottom" />
    <DxChartTooltip Enabled="true" Position="RelativePosition.Outside">
        <div style="margin: 0.75rem">
            <div class="font-weight-bold">@(((DateTime)context.Point.Argument).ToString("d"))</div>
            <div>1$ = @(context.Point.Value)¥</div>
        </div>
    </DxChartTooltip>
</DxChart>

@code {
    IEnumerable<BargainDataPoint> UsdJpyData;
    @inject ICurrencyExchangeDataProvider UsdJpyDataProvider

    protected override async Task OnInitializedAsync() {
        UsdJpyData = await UsdJpyDataProvider.GetDataAsync();
    }
}

public class BargainDataPoint {
    public DateTime DateTimeStamp { get; }
    public double Price { get; }

    public BargainDataPoint(DateTime dateTimeStamp, double price) {
        DateTimeStamp = dateTimeStamp;
        Price = price;
    }
}

Data Aggregation

Run Demo: Charts - Zoom and Pan

Aggregation vs Summaries

You can also use summary methods to decrease the number of visible points and optimize chart performance.

The table below describes the difference between aggregation and summaries.

	Aggregation	Summaries
Points to Group	The chart aggregates points with different argument values (on a specific interval of X-axis).	The chart calculates summaries for points with the same argument value.
Behavior on Zoom	The chart aggregates data when it loads them and re-aggregates data when users zoom the chart.	The chart calculates summaries only when it loads data.

If you use an aggregation method and a summary method in the same series, the chart first calculates summaries and then uses result values as initial values for aggregation.