Teechartpro 7.12 Drawing a graph

[Clara Genermont]

Hi Narcis,

Can we draw the graph of any function with
teechart directly with his equation?


Thank you for your help

Didier

[Narcís]

Hi Didier,

Yes, you can use custom function. You'll find an example at All Features\Welcome!\Functions\Extended\Custom y=f(x) in the new features demo, available at TeeChart's program group.

[Clara Genermont]

thank you Narcis,

but I can't draw a function like this

y=2+3*(1+x)-5 + (abs(-x^2) - x*x) * 2 - 1/(x + 1)
or yet
y=sinx + cosx - abs(tanx) + x

How can draw them ?

I don't understand how to intoduce this equation...

Can you show me an example ?

thank you very much for your help

Didier

[Yeray]

Hi Clara,

This works for me here.

Code: Select all

procedure TForm1.TeeFunction1Calculate(Sender: TCustomTeeFunction;
  const x: Double; var y: Double);
begin
  //y := 2+3*(1+x)-5 + (abs(power(-x,2)) - x*x) * 2 - 1/(x + 1);
 y := sin(x) + cos(x) - abs(tan(x)) + x;
end;

[Clara Genermont]

sorry but
what is TeeFunction1Calculate ?
event, object or a component ?

thank you in advance

[Yeray]

Hi Didier,

It's an event for TCustomTeeFunction. You should find it through Object inspector as usually if you added the function at design time (at the function object, not the series).

[Clara Genermont]

Yès, il found it and I choose Y= f(x)

but Idon't see the event ! (F11 on the Teechart)

thanks

Didier

[Marc]

Hello Didier,

When the function has been selected by editor, close the editor and F11 will take you to the object inspector. Select 'TeeFunction1' from the drop-down combobox and click on the Object Inspector's Events tab. From here you can select the event.

Regards,
Marc Meumann

[Clara Genermont]

I don't see the event
I choose "functions" and "y = f(x)"

then in the combobox I see Y= f(x) not TeeFunction1
and on F11

I don't see "OnCalculate"

????

nb:
version 7.12[/url]

[Yeray]

Hi Didier,

That's strange. You should see a series and a teefunction.
Another test you can do could be to add a chart (and a function) to a new form at design time and see the declarations in the code generated. For me:

Code: Select all

 //...
type
  TForm1 = class(TForm)
    Chart1: TChart;
    Series1: TLineSeries;
    TeeFunction1: TCustomTeeFunction;
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
//...

[Clara Genermont]

yès !

that's good !!!

I had a little concern with the installation...

THANK YOU VERY MUCH

[Yeray]

Hi Didier,

I'm happy to see that!

[Narcís]

Hi Didier,

Please notice that I have splitted your last post into a new topic:

http://www.teechart.net/support/viewtopic.php?t=8798

It's better starting a new topic for each now issue. It's easier to follow up.

[nitin]

Hi Narcis,

How can I Draw this function with TeeFunction1Calculate
with three parameters :

Qf, S, Sa that can be defined by double
(exemple : Qf = 1, S = 8, Sa =4,3)

Code: Select all

y := (Qf * S * 0.36 * x) / Sa;

for this moment, I have a message "operation en virgule flottante incorrecte"

Thank you for your help

Didier

[Narcís]

Hi Didier,

You can do this:

Code: Select all

procedure TForm1.TeeFunction1Calculate(Sender: TCustomTeeFunction;
  const x: Double; var y: Double);
const
  Qf = 1;
  S = 8;
  Sa = 4.3;
begin
  y := (Qf * S * 0.36 * x) / Sa;
end;

If those constants need to be modified then you can create them as global variables in your unit.

Hope this helps!