Calculating the Function Value Using the Calculate Method

As an alternative to the use of either a code string or events, the programmer may specify an instance of an object that implements C1.Win.C1Chart.ISimpleFunction interface. Such an object must inherit from the interface and implement a public function name, Calculate. The method, Calculate takes the independent variable (Double) as a parameter and returns the dependent variable (Double).

For the YFunction class objects, the CustomFunction property must be set to the ISimpleFunction implementation object. For the ParametricFunction class object, the CustomFunctionX and CustomFunctionY properties must be set to appropriate objects implementing the ISimpleFunction interface.

· Visual Basic

Private Sub Button_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles Button.Click

Dim yf As C1.Win.C1Chart.YFunction = New C1.Win.C1Chart.YFunction()

yf.CustomFunction = New CustomFunction()

yf.MinX = -5

yf.MaxX = 5

yf.LineStyle.Color = Color.DarkGreen

yf.LineStyle.Thickness = 3

C1Chart1.ChartGroups(0).ChartData.FunctionsList.Add(yf)

End Sub

Public Class CustomFunction

Implements C1.Win.C1Chart.ISimpleFunction

Public Function Calculate(ByVal x As Double) As Double _
Implements C1.Win.C1Chart.ISimpleFunction.Calculate

Return -x * x * x ' y = - x*x*x

End Function

End Class

· C#

private void button_Click(object sender, System.EventArgs e)

{

C1.Win.C1Chart.YFunction yf = new C1.Win.C1Chart.YFunction();

yf.MinX = -5;

yf.MaxX = 5;

yf.LineStyle.Color = Color.DarkGreen;

yf.LineStyle.Thickness = 2;

yf.CustomFunction = new CustomFunction();

c1Chart1.ChartGroups[0].ChartData.FunctionsList.Add( yf);

}

class CustomFunction : C1.Win.C1Chart.ISimpleFunction

{

public double Calculate( double x)

{

return -x*x*x; // y = -x*x*x

}

· Delphi

type

CustomFunction = class(TObject, C1.Win.C1Chart.ISimpleFunction)

public

function Calculate(x: double): double;

end;

implementation

function CustomFunction.Calculate(x: double): double;

begin

Result := -x*x*x; // y = -x*x*x

end;

procedure button_Click(sender: System.Object; e: System.EventArgs);

var

yf: C1.Win.C1Chart.YFunction;

begin

yf := C1.Win.C1Chart.YFunction.Create;

yf.MinX := -5;

yf.MaxX := 5;

yf.LineStyle.Color := Color.DarkGreen;

yf.LineStyle.Thickness := 2;

yf.CustomFunction := CustomFunction.Create;

C1Chart1.ChartGroups[0].ChartData.FunctionsList.Add(yf);

end;