MATLAB Curve Fitting (Ellipse-like)

Question

I need to fit 10 data points (x,y) into this equation:

ay² + bxy + cx + dy + e = x²

It\'s told that this is a ellipse-like equ

Answer 1

It is a linear system with variables [a b c d e]. You can use \ to solve it:

 x=rand(10,1);
 y=rand(10,1);
 [y.^2,x.*y,x,y,ones(numel(x),1)]\x.^2

ans =

   -0.4437 %% a
    1.1034 %% b
    0.5337 %% c
   -0.2808 %% d
    0.0402 %% e

Answer 2

Give this a shot:

http://www.mathworks.com/matlabcentral/fileexchange/3215-fitellipse