function [WJt, VJ0t] = modwt_inv_cir_shift(TWJt, TVJ0t, wtfname, J0)% modwt_inv_cir_shift --  Inverse circularly shift (advance) MODWT coefficients.%%****f* wmtsa.dwt/modwt_inv_cir_shift%% NAME%   modwt_inv_cir_shift --  Inverse circularly shift (advance) MODWT coefficients.%% SYNOPSIS%% INPUTS%   TWJt         -  NxJ array of circularly-shifted MODWT wavelet coefficents.%                   where N = number of time intervals.%                         J = number of levels.%   TVJ0t        -  Nx1 vector of circularly-shifted MODWT scaling%                   coefficients at level J0.%   wtfname      -  name of a supported WMSTA wavelet filter.%   J0           -  largest or partial level of MODWT.%% OUTPUTS%   WJt          -  NxJ array of MODWT wavelet coefficents.%   VJ0t         -  Nx1 vector of MODWT scaling coefficients at level J0.%%% SIDE EFFECTS%%% DESCRIPTION%%% EXAMPLE%%% NOTES%   If WJ is not supplied, user must supply value of J0.%%% ALGORITHM%   See pages 114-115 equation 114b of WMTSA.%% REFERENCES%   Percival, D. B. and A. T. Walden (2000) Wavelet Methods for%     Time Series Analysis. Cambridge: Cambridge University Press.%% SEE ALSO%  advance_scaling_filter, advance_wavelet_filter,%  advance_time_series_filter, modwt%% AUTHOR%   Charlie Cornish%% CREATION DATE%   2003-05-24%%% COPYRIGHT%%% REVISION%   $Revision: 612 $%%***% $Id: modwt_inv_cir_shift.m 612 2005-10-28 21:42:24Z ccornish $    usage_str = ['Usage:  [WJt, VJ0t] = ', mfilename, ...               '(TWJt, TVJ0t, wtfname, J0)'];  %%  Check input arguments and set defaults.  error(nargerr(mfilename, nargin, [3:4], nargout, [0:2], 1, usage_str, 'struct'));  if (~exist('wtfname', 'var') || isempty(wtfname))    error('Must provide a value for wtfname argument');  end  WJt = [];if (exist('TWJt', 'var') && ~isempty(TWJt) )  [N, J] = size(TWJt);  WJt = zeros(size(TWJt));  for (j = 1:J)    nuHj = advance_wavelet_filter(wtfname, j);    inv_nuHj = -nuHj;    WJt(:,j) = circshift(TWJt(:,j), inv_nuHj);  endend  if (exist('TVJ0t', 'var') && ~isempty(TVJ0t) )  if (exist('J', 'var'))    J0 = J;  else    if (~exist('J0', 'var') || ~isempty(J0))      error(['Must specify J0 if supplying only scaling coefficients ' ...             'J0']);    end  end    nuGj = advance_scaling_filter(wtfname, J0);  inv_nuGj = -nuGj;  VJ0t = circshift(TVJ0t, inv_nuGj);endreturn