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Re: Fitting Circles
- Subject: Re: Fitting Circles
- From: Vince Hradil <hradilv(at)yahoo.com>
- Date: Wed, 01 Dec 1999 10:39:20 -0600
- Newsgroups: comp.lang.idl-pvwave
- Organization: Abbott Labs Pharmaceutical Products Division
- References: <email@example.com>
- Xref: news.doit.wisc.edu comp.lang.idl-pvwave:17564
How about doing a transformation and solving a simpler problem:
What you want to fit is r0 = [(x-x0)^2+(y-y0)^2]^(0.5)
r0 - [(x-x0)^2+(y-y0)^2]^(0.5)
for all pairs of (x,y). This can be done using your favorite fitting
routine (I like Craig markwardt's MPFIT... routines,
> Dear Colleagues,
> I am trying to fit a circle to a set of points (x,y), and from this
> determine the centre point (x0,y0) and radius r0. It is also very
> important that I obtain the standard deviations or errors in the x0,y0
> and r0.
> So far, I have looked at the idl routine, curvefit.pro.
> This is a useful program but doesn't seem to allow you to pass 2
> independent variables x and y.
> I was wondering if someone has written something similar in idl,
> or could suggest a way to solve this problem.
> Fraser Hatfield
> University of Leeds, UK.
> Sent via Deja.com http://www.deja.com/
> Before you buy.