#### Topic: i need help !

first of all i want to say you did an amazing job with this program,
you have all my congratulations.

I don't know if this is the wright place to put this question but i really need your help and i will appreciate this as much as i can.

I need some advices with my applications that I'm currently working at.

I just want to recreate a similar Cartesian plane like the one in your application.

Could you tell me some of the basic that i should guide upon ? I mean, how to establish a Cartesian plane from the world plane in the case of a form.

The form draws items from its left-upper corner. I know how to set the origin of the system in the middle of the form. I also know that i need to reflect the y-axis to get the Cartesian system. I want to make my custom coordinate system, with my own ticks, etc.

If you could point me into the wright direction from the source code point of view.

Thanks for your understanding. Again good job with the program.

#### Re: i need help !

No, this is not the right place to ask programming questions. I suggest you find a forum or newsgroup for the programming language or tool you want to use.

You can of course look at the source code for Graph. It can be found at http://sourceforge.net/projects/graph/files/ but I do not expect that you will find much use for it.

But it sounds like you already figured the basic out. You need to map the Cartesian coordinates to image coordinates. In short it can be done like this, where (x,y) is the Cartesian coordinate and (X,Y) is the image coordinate:

``````X = (x-xMin) * ImageWidth / (xMax-xMin)
Y = (yMax-y) * ImageHeight / (yMax-yMin)``````

#### Re: i need help !

So i just have to create an image object with my own width and height, draw the system (Cartesian) to the image and then draw the image to my form ?

something like this i think:

Bitmap bmp = new Bitmap (bmpWidth, bmpHeight);
Graphics g = Graphics.FromImage(bmp);

g.DrawLine(...);      //using a function that maps points from Cartesian to image.
g.DrawString(...);

Graphics frmGraphics = Form1.CreateGraphics();

frmGraphics.DrawImage(bmp, 0, 0, bmpWidth, bmpHeight);

Thank you, again. I'll give it a try.

#### Re: i need help !

Yes, that is more or less what Graph does.

Thank you.