Creating Arcs by Center, Radius, and Arc angle

[theBFG]

Is there a way to create (script)  an arc by center, radius and arc angle?  or by 3 points?

By arc i mean a regular arc, as in a piece of a circle.  It seems the native illustrator tools make it very difficult to create a regular arc in the normal CAD way of drawing one.  I found a forum post from a guy years ago that said he had created script to make arcs this way.  Have you come across this anywhere? Any ideas?

Thanks,

[Ten A · Accepted solution]

There is a sample, create an arc.

var lnColor = new GrayColor;

lnColor.gray = 100;

var r =100; //radius

var ln = app.activeDocument.pathItems.add ();

ln.stroke = true;

ln.strokeColor = lnColor;

ln.strokeWidth = 0.3;

ln.filled =false;

var pt = ln.pathPoints.add()

pt.anchor = Array(0, 100);

pt.rightDirection = Array((Math.sqrt (2)-1)/3*4*r, 100);

pt = ln.pathPoints.add();

pt.anchor = Array(100, 0);

pt.leftDirection = Array(100, (Math.sqrt (2)-1)/3*4*r);

Read below article.

Way to tell perfect circle from an ellipse?

and I think, you'd better read this page.

http://en.wikipedia.org/wiki/B%C3%A9zier_curve