Dragging and changing a curve (image)

[Jim Hurley]

>
>Message: 9
>Date: Wed, 14 Apr 2004 14:36:32 +0200
>From: Beat Cornaz <beat.c at hetnet.nl>
>Subject: Re : Dragging and changing a curve (image)
>To: Revolution group <use-revolution at lists.runrev.com>
>Message-ID: <a05100300bca2ddeefe4f@[195.121.130.235]>
>Content-Type: text/plain; charset="us-ascii" ; format="flowed"
>
>>I know that Alejandro has developed a bezier function for RR. It is 
>>very cool.
>
>>If you want to just plot a known function, I would recommend my
>  >favorite graphics tool, Turtle Graphics.
>
>>The code to implement TG is on my web site at
>>http://home.infostations.net/jhurley/ under Turtle Graphics.
>
>>Jim
>
>
>Thanks Jim,
>your turtle Graphics works fine from what I've tried and is a
>valuable tool for me. It doesn't solve the problem I'm facing though.
>
>I want to be able to change the shape of a curve by interacting with
>it on screen with the mouse. At the same time I need to know the
>algebraic formula of the curve (the changed one (the new one)) in
>order to do calculations with it. Let's say I start out with y =
>3x^0.9 + 12. As soon as I change the curve with the mouse, I need to
>know the new formula (f.i. y = 3x^1.2 + 33).
>
>       The curve is just a visual rerpesentation of something on the
>screen, but needs to changed a lot. Of course I can do that with
>sliders (that's the way I do it now) but it would be so much neater
>to be able to click and drag-change the curve.
>
>I'm VERY INTERESTED in the Bezier function by Alejandro. Where can I
>get that one?


Beat,

Check out Alejandro's web site at

http://www.geocities.com/capellan2000/

Look for Bezier.  It is very clever.  You should be able to extract 
the bezier curve parameters and put the equation in a field.

Jim