Steema Central

Posted: **Mon Nov 24, 2008 10:54 am**

Hi Narcis,

I would build a program in delphi with TeeChart so that the user can enter the aquatic function and click on a display its image.

How will introduce the equation y:= f (x) in the code of the event
TForm1.TeeFunction1Calculate (Sender: TCustomTeeFunction;
CONST x: Double; VAR y: Double);

knowing it will be in the form of text there 'y:= f (x) '?

thank you for your help

Didier

Posted: **Mon Nov 24, 2008 11:30 am**

Hi Didier,

You can use StrToFloat method for that, for example:

Code: Select all

procedure TCustomFunctionDemo.TeeFunction1Calculate(Sender: TCustomTeeFunction;
  const x: Double; var y: Double);
begin
  y:=StrToFloat('Sin(x/10)');
end;

Posted: **Mon Nov 24, 2008 3:58 pm**

Thank you Narcis !

another question :

how to revive the event "TeeFunction1Calculate"
because neither the repaint nor the invalidate work?

Didier

Posted: **Mon Nov 24, 2008 5:16 pm**

Hi Didier,

You can try refreshing function's series datasource, for example:

Code: Select all

Series2.CheckDataSource;

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