plane_fit

Fits a plane of the from z=Ax+By+C to the data and provides the coefficients A,B and C. The functions uses the svd command (singular value decomposition).

%% EXAMPLE
[x,y]=meshgrid(linspace(0,10,20),linspace(0,10,20));
a=1; b=2; c=-2;
z=(a*x)+(b*y)+c;
x=x(:); y=y(:); z=z(:);
z=z+(randn(length(z),1));
[A,B,C]=plane_fit(x,y,z);
[X,Y]=meshgrid(linspace(min(x),max(x),20),linspace(min(y),max(y),20));
Z=(A*X)+(B*Y)+C;
plot3(x,y,z,'r.'); hold on; grid on;
surf(X,Y,Z,'FaceColor','g'); alpha(0.5);
title(['a=',num2str(a), ', A=',num2str(A),', b=',num2str(b),', B=',num2str(B),', c=',num2str(c),', C=',num2str(C)]);