oothing windows have constant half-width
         (or radius) 2. Note that h is applied after scaling.

   'pen' penalty parameter for adaptive smoothing. Needs to be used
         with care.

  'alpha' The old way of specifying smoothing parameters, as used in
         my book. alpha is equivalent to the vector [nn,h,pen].
         If multiple componenents are non-zero, the largest corresponding
         bandwidth is used. The default (if none of alpha,nn,h,pen
         are provided) is [0.7 0 0]