function pointtracker_eval()

N = 10000;

mu   = 0.5;

variance = 0.01;
IQ = [0.707; 0.707];
IQ_n = repmat(IQ, 1, N) + variance*randn(2,N)/sqrt(12);
size(IQ_n)
ref = [1; 1];

for n=1:N,
    d(n) = sqrt(sum((IQ_n(n) - ref).^2));	
    ref = ref + mu*(IQ_n(n)-ref);
end;

ref
close all;
plot(IQ_n(1,:), IQ_n(2,:), '.', ref(1), ref(2), 'r.'); grid;

figure;

plot(1:N, d); grid;