function [k, b] = linefit(x, y)
    n = length(x);
    x = reshape(x, n, 1);
    y = reshape(y, n, 1);
    A = [x, ones(n, 1)];
    bb = y;
    B = A' * A;
    bb = A' * bb;
    yy = B \ bb;
    k = yy(1);
    b = yy(2);
end