==> stddevfft.pro <==
function stddevfft, x
  return, sqrt(total((abs(fft(x))^2)[1:-1]))
end

==> stddevsum.pro <==
function stddevsum, x
  return, sqrt(mean(x^2) - mean(x)^2)
end
% Compiled module: STDDEVSUM.
% Compiled module: MEAN.
% Compiled module: STDDEVFFT.
      1.15258      1.15258
