Hi Anthony, from what I can see that you have drawn there, it looks like you are not using "The Draftsman's Method" as described in that previous link ( http://www.uwgb.edu/dutchs/MATHALGO/Ellipses.HTM) but rather the "Five-Center Method", is that correct?
The page there mentions the following:
quote: "The true ellipse is shown in red, the approximation in purple. The approximation is quite good for slightly or moderately eccentric ellipses but becomes obviously incorrect for very elongated ellipses."
So yes as far as I can tell that method produces a pretty rough approximation which gets worse as the width to height ratio increases.
An ellipse is a continuously changing curve and you simply cannot make a very good approximation of a rather elongated one using only a couple of arc pieces...
- Michael |
