%N hannsm %F $MIR/src/subs/hann.for
%D Hanning smooth a data array..
%P nebk
%: smoothing, convolution
%B
      subroutine hannsm (nsmth, coeffs, npts, arr, work)

      implicit none
      integer npts, nsmth
      real arr(npts), work(nsmth), coeffs(nsmth)

  Hanning smooth an array.

  Input:
    nsmth    i    Smoothing length.  SHould be odd integer.
    coeffs   r    Weights.
    npts     i    Number of data points.
  Input/output:
    arr      r    Data array.  Contains smoothed result on output
    work     r    Work array. Must be at least of size NSMTH
