comp.lang.idl-pvwave archive
Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado

Home » Public Forums » archive » Minimum area ellipse - quadratic optimisation?
Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend 
Return to the default flat view Create a new topic Submit Reply
Minimum area ellipse - quadratic optimisation? [message #47561] Thu, 16 February 2006 06:19 Go to previous message
Olivia is currently offline  Olivia
Messages: 16
Registered: February 2006
Junior Member
Dear All,

My aim is to fit an ellipse with a known center onto a distribution of
points, where all points have to be inside or on the ellipse, and the
ellipse chosen is of the minimum area.

I thought a brute force and not very clever way of doing this would be
to calculate the area taking each set of 3 points to solve the 3
remaining unknowns, (a, b, and orientation angle), in the ellipse
equation, and finding which one had the smallest area. But this
wouldn't work obviously as there would be no condition that all the
other points have to be inside the ellipse. I have read up on quadratic
optimization but have to admit I do not really understand the maths.

I posted on this topic before, but it is important that my ellipse
fitting method does not rely on convex hulls. I wrote a program which
does fit ellipses to the point distributions, but not the ellipses with
the minimum area.

I am sure the problem can't be as hard as I am finding it, and I am
feeling right now like drawing the 600 or so ellipses my program needs
myself! Any suggestions really would be very helpful. Thanks,

Olivia
[Message index]
 
Read Message
Read Message
Read Message
Read Message
Previous Topic: singleton usage
Next Topic: IDL Graphics Objects & Heap Variables

-=] Back to Top [=-
[ Syndicate this forum (XML) ] [ RSS ] [ PDF ]

Current Time: Wed Oct 08 19:48:13 PDT 2025

Total time taken to generate the page: 0.00456 seconds