SummaryFunctionArgumentDescription(String, ScaleType) Constructor
Initializes a new instance of the SummaryFunctionArgumentDescription class with the specified name and scale type.
Namespace: DevExpress.XtraCharts
Assembly: DevExpress.XtraCharts.v24.1.dll
NuGet Package: DevExpress.Charts
Declaration
Parameters
Name | Type | Description |
---|---|---|
name | String | A String that specifies the name of the argument. |
scaleType | ScaleType | A ScaleType enumeration value, which specifies the scale type for the function argument. For example, if the scale type is ScaleType.Numerical, only numerical fields will be shown for the Summarization function editor in the chart wizard. |
Example
The following example demonstrates how to create a custom summary function, which returns an OHLC point calculated by the passed array of values. To accomplish this task, create a SummaryFunction delegate and register it using the ChartControl.RegisterSummaryFunction method:
// Declare the Financial summary function.
private static SeriesPoint[] CalculateProductValue(
Series series,
object argument,
string[] functionArguments,
DataSourceValues[] values,
object[] colors
) {
string functionArgument = functionArguments[0];
int lastIndex = values.Length - 1;
double open = Convert.ToDouble(values[0][functionArgument], CultureInfo.InvariantCulture);
double close = Convert.ToDouble(values[lastIndex][functionArgument], CultureInfo.InvariantCulture);
double high = Math.Max(open, close);
double low = Math.Min(open, close);
for (int i = 1; i < lastIndex; i++) {
high = Math.Max(high, Convert.ToDouble(values[i][functionArgument], CultureInfo.InvariantCulture));
low = Math.Min(low, Convert.ToDouble(values[i][functionArgument], CultureInfo.InvariantCulture));
}
// Return the result.
return new SeriesPoint[] {
new SeriesPoint(argument, high, low, open, close)
};
}
private void Form1_Load(object sender, EventArgs e) {
chartControl.DataSource = new CurrencyRateLoader("../../Data/EurUsdRate.xml").Load();
// Register the summary function in a chart.
chartControl.RegisterSummaryFunction(
name: "FINANCIAL",
displayName: "Financial",
resultScaleType: ScaleType.Numerical,
resultDimension: 4,
argumentDescriptions: new SummaryFunctionArgumentDescription[] {
new SummaryFunctionArgumentDescription("Value", ScaleType.Numerical)
},
function: CalculateProductValue
);
Series series = chartControl.Series["EurUsd"];
series.ArgumentDataMember = "DateTime";
// Note that ValueDataMembers are not specified.
series.DateTimeSummaryOptions.SummaryFunction = "FINANCIAL([Value])";
}