function [cout]=comp_irdgtii(cin,a)
%COMP_IRDGTII Compute inverse real DGT type II
%
%
%   Url: http://ltfat.github.io/doc/comp/comp_irdgtii.html

% Copyright (C) 2005-2015 Peter L. Soendergaard <peter@sonderport.dk>.
% This file is part of LTFAT version 2.1.1
%
% This program is free software: you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation, either version 3 of the License, or
% (at your option) any later version.
%
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with this program.  If not, see <http://www.gnu.org/licenses/>.

M=size(cin,1);
N=size(cin,2);
W=size(cin,3);
L=N*a;

Mhalf=ceil(M/2);
Mend=Mhalf*2-1;

cout=zeros(M,N,W,assert_classname(cin));

% Copy the first coefficient, it is real
cout(1,:,:)=cin(1,:,:);

cout(2:Mhalf,:,:)=(cin(2:2:Mend,:,:)- i*cin(3:2:Mend,:,:))/sqrt(2);
cout(M-Mhalf+2:M,:,:)= -(cin(Mend-1:-2:2,:,:)  +i*cin(Mend:-2:3,:,:))/sqrt(2);

% If f has an even length, we must also copy the Nyquest-wave
% (it is imaginary)
if mod(M,2)==0
  cout(M/2+1,:,:)=-i*cin(M,:,:);
end;




