%  Hebb rule with 2 D rotated input
eta=0.1;
theta=pi/3;
R=[cos(theta),sin(theta);-sin(theta),cos(theta)];
sig1=1;
sig2=0.3;
Iterations =300;
figure
hold on
w=0.01*rand(2,1);
w_all=w;
Q=zeros(2);
axis 'square'
for ii=1:Iterations
    x1=sig1*(2*rand-1);
    x2=sig2*(2*rand-1);
    x=[x1,x2]*R;
    Q=Q+x'*x;
    plot(x(1),x(2),'+');
    y=x*w;
    w=w+eta*(y*x'-y^2*w);
    %w=[w,w_new]
    w_all=[w_all,w];
    plot(w(1),w(2),'or')
    pause(.02)
    drawnow
end
Q=Q/Iterations
[a,b]=eig(Q)
   h1=plot([0 a(1,2)],[0 a(2,2)],'g') 
   h2=plot([0 a(1,1)],[0 a(2,1)],'-.k')
set(h1,'LineWidth',3)
set(h2,'LineWidth',3)