% Power estimation on discrete signals
function y = rms(x,Nw)

N = length(x);
y = zeros(1,N);

y(1) = x(1)^2;

for k = 2:N-Nw,
  for n = k:Nw+k,
    y(n) = y(n-1)*(1-1/Nw) + 1/Nw*x(n)^2;
  end;
end;