You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: modwtjm.m
    path of file: ./repos/bspm/thirdparty/brainwavelet_v1.1_fMRI_OSX/third_party/wmtsa/dwt
    
    the code of the file until where you have to start completion: function [Wtout, Vtout] = modwtjm(Vtin, ht, gt, j)
% modwtjm -- Calculate jth level MODWT coefficients (MATLAB implementation).
%
%****f* wmtsa.dwt/modwtjm
%
% NAME
%   modwtjm -- Calculate jth level MODWT coefficients (MATLAB implementation).

    
function [Wtout, Vtout] = modwtjm(Vtin, ht, gt, j)
% modwtjm -- Calculate jth level MODWT coefficients (MATLAB implementation).
%
%****f* wmtsa.dwt/modwtjm
%
% NAME
%   modwtjm -- Calculate jth level MODWT coefficients (MATLAB implementation).
%
% SYNOPSIS
%   [Wtout, Vtout] = modwtjm(Vtin, ht, gt, j)
%
% INPUTS
%   * Vtin        -- Input series for j-1 level (i.e. MODWT scaling coefficients) 
%   * ht          -- MODWT wavelet filter coefficients.
%   * gt          -- MODWT scaling filter coefficients.
%   * j           -- level (index) of scale.
%
% OUTPUTS
%   * Wtout       -- MODWT wavelet coefficients for jth scale.
%   * Vtout       -- MODWT scaling coefficients for jth scale.
%
% SIDE EFFECTS
%
%
% DESCRIPTION
%   modwtjm is an implementation in MATLAB code of the MODWT transform for 
%   the jth level, and is included in the toolkit for illustrative purposes 
%   to demonstrate the pyramid algothrim.
%
%   For speed considerations, the modwt function uses the C implementation of 
%   the MODWT transform, modwtj, which linked in as a MEX function.
%
% EXAMPLE
%   X = wmtsa_data('ecg');
%   wtf = modwt_filter('la8');
%   % Compute the j = 1 level coefficients for ECG time series.
%   j = 1;
%   [Wtout, Vtout] = modwtjm(X, wft.h, wtf.g, j);
%
% WARNINGS
%
%
% ERRORS
%
%
% NOTES
%
%
% BUGS
%
%
% TODO
%
%
% ALGORITHM
%   See page 177-178 of WMTSA for pyramid algorithm.
%
% REFERENCES
%
%
% SEE ALSO
%   modwtj, modwt, modwt_filter
%
% TOOLBOX
%   wmtsa
%
% CATEGORY
%   dwt
%

% AUTHOR
%   Charlie Cornish
%
% CREATION DATE
%   2005-01-12
%
% COPYRIGHT
%   
%
% CREDITS
%
%
% REVISION
%   $Revision: 612 $
%
%***

%   $Id: modwtjm.m 612 2005-10-28 21:42:24Z ccornish $

  usage_str = ['Usage:  [Wtout, Vtout] = ', mfilename, ...
             '(Vtin, ht, gt, j)'];
  
  %%  Check input arguments and set defaults.
  error(nargerr(mfilename, nargin, [4:4], nargout, [0:2], 1, usage_str, 'struct'));

  N = length(Vtin);
  L = length(ht);
  
  Wtout = zeros(N, 1) * NaN;
  Vtout = zeros(N, 1) * NaN;
  
  for (t = 1:N)
    k = t;
    Wtout(t) = ht(1) * Vtin(k);
    Vtout(t) = gt(1) * Vtin(k);
    
    for (n = 2:L)
      k = k - 2^(j-1);
      if (k < 1)
        k = k + N;
      end