code: def window_nuttall(N):
      r
      a0 = 0.355768
      a1 = 0.487396
      a2 = 0.144232
      a3 = 0.012604
  
      return _coeff4(N, a0, a1, a2, a3)
docs: r"""Nuttall tapering window
  
      :param N: window length
  
      .. math:: w(n) = a_0 - a_1 \cos\left(\frac{2\pi n}{N-1}\right)+ a_2 \cos\left(\frac{4\pi n}{N-1}\right)- a_3 \cos\left(\frac{6\pi n}{N-1}\right)
  
      with :math:`a_0 = 0.355768`, :math:`a_1 = 0.487396`, :math:`a_2=0.144232` and :math:`a_3=0.012604`
  
      .. plot::
          :width: 80%
          :include-source:
  
          from spectrum import window_visu
          window_visu(64, 'nuttall', mindB=-80)
  
  
      .. seealso:: :func:`create_window`, :class:`Window`