fitline.m

Line & Curve Fitting To 2D Points

function [x,y,beta,alpha] = fitLine(X,n)
meanX = sum(X(:,1))/n;
meanY = sum(X(:,2))/n;
P1 = (X(:,1) - meanX) .* (X(:,2)-meanY);
s1 = sum(P1);
P2 = (X(:,1)-meanX) .^ 2;
s2 = sum(P2);
beta = s1/s2;
alpha = meanY - beta * meanX;
x = 0:0.01:1;
y = beta * x + alpha;

end

% X = rand(n,3);
% Mat = [ones(size(X(:,1))),X(:,1),X(:,2)];
% A = Mat\X(:,3);
% x1 = 0:0.001:1;
% x2 = 0:0.001:1;
% Y = A(1) + A(2)*x1+ A(3)*x2;
% plot3(X(:,1),X(:,2),X(:,3),'o',x1,x2,Y)
% grid on;