Find the centre and the radius of the circle or ellipse

I have these 3D data (attached) which represents the points of an ellipse or a circle (it is not exactly a circle).

How can I find the centre and the radius of this ellipse ?

Answer 1

[Matt J]

You can download this,

https://www.mathworks.com/matlabcentral/fileexchange/87584-object-oriented-tools-for-fitting-conics-and-quadrics

and use ellipticalFit().

load('ellipse_circle_3Ddata.mat')

pFit=planarFit(data);

eFit=ellipticalFit(pFit.project2D(data))

Center3D=pFit.unproject3D(eFit.center(:))'

efit =

ellipticalFit with properties:

center: [1.9450e+05 7.1093e+04]

a: 2.6560e+07

b: 2.6559e+07

angle: 15.8694

Center3D =

1.0e+05 *

-1.2707 1.6117 -0.2764