[求助]matlab求圆心坐标
 

已知模型为(x-a)^2+(y-b)^2=r^2，给出十组x,y
，怎么编程求a,b,r:confused:

function [xc,yc,R,a] = circfit(x,y)
%CIRCFIT Fits a circle in x,y plane
% [XC, YC, R, A] = CIRCFIT(X,Y)
% Result is center point (yc,xc) and radius R.A is an

% optional output describing the circle's equation:
% x^2+y^2+a(1)*x+a(2)*y+a(3)=0

n=length(x);
xx=x.*x;
yy=y.*y;
xy=x.*y;
A=[sum(x) sum(y) n;sum(xy) sum(yy) sum(y);sum(xx) sum(xy) sum(x)];
B=[-sum(xx+yy) ; -sum(xx.*y+yy.*y) ; -sum(xx.*x+xy.*y)];
a=A\B;
xc = -.5*a(1);
yc = -.5*a(2);
R = sqrt((a(1)^2+a(2)^2)/4-a(3));