Circle Perimeter Formula

[John]

Hi there,

Can anyone tell me how to construct a shapesheet formula to a Control, on a
Circle shape, so that it will track the perimeter of the shape?

I'm afraid I should have paid more attention in my Trigonometry class!

Many thanks

John

 

[JuneTheSecond]

One idea might be to use snap power,though it is weak.
Make a control point on a line whose start point follows. This control point
sticks when the control point goes to near the circle.

 

[John]

Thanks June, but I really need a mathematical formula that will describe the
circle's perimeter so the user cannot drag it off somewhere else?

Best regards

John

 

[Al Edlund]

I'd start by checking height and width of the shape to make sure it's not an
ellipse, and then just grab either of them as the diameter,
last time I looked wasn't it diameter times pi (3.14159...)
al

Thanks June, but I really need a mathematical formula that will describe
the circle's perimeter so the user cannot drag it off somewhere else?

Best regards

John

 

[John]

Hi Al,

After reponding to June's post I've been thumbing through Graham Wideman's
book and it turns out there's a perfect example on page 136 (Vis 2003 book),
but thank you for your response as well.

Best regards

John

I'd start by checking height and width of the shape to make sure it's not
an ellipse, and then just grab either of them as the diameter,
last time I looked wasn't it diameter times pi (3.14159...)
al