1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
function [f]=comp_idwiltiii(coef,g)
%-*- texinfo -*-
%@deftypefn {Function} comp_idwiltiii
%@verbatim
%COMP_IDWILTIII Compute Inverse discrete Wilson transform type III.
%
% This is a computational routine. Do not call it
% directly.
%@end verbatim
%@strong{Url}: @url{http://ltfat.github.io/doc/comp/comp_idwiltiii.html}
%@end deftypefn
% Copyright (C) 2005-2016 Peter L. Soendergaard <peter@sonderport.dk>.
% This file is part of LTFAT version 2.3.1
%
% 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/>.
% AUTHOR : Peter L. Soendergaard.
% TESTING: OK
% REFERENCE: OK
M=size(coef,1);
N=size(coef,2);
W=size(coef,3);
a=M;
L=N*M;
coef2=zeros(2*M,N,W,assert_classname(coef,g));
coef2(1:2:M,1:2:N,:) = exp( i*pi/4)*coef(1:2:M,1:2:N,:);
coef2(2*M:-2:M+1,1:2:N,:) = exp(-i*pi/4)*coef(1:2:M,1:2:N,:);
coef2(1:2:M,2:2:N,:) = exp(-i*pi/4)*coef(1:2:M,2:2:N,:);
coef2(2*M:-2:M+1,2:2:N,:) = exp( i*pi/4)*coef(1:2:M,2:2:N,:);
coef2(2:2:M,1:2:N,:) = exp(-i*pi/4)*coef(2:2:M,1:2:N,:);
coef2(2*M-1:-2:M+1,1:2:N,:) = exp( i*pi/4)*coef(2:2:M,1:2:N,:);
coef2(2:2:M,2:2:N,:) = exp( i*pi/4)*coef(2:2:M,2:2:N,:);
coef2(2*M-1:-2:M+1,2:2:N,:) = exp(-i*pi/4)*coef(2:2:M,2:2:N,:);
% Apply the generalized DGT and scale.
%f=comp_igdgt(coef2,g,a,2*M,L,0,.5,0,0)/sqrt(2);
f = comp_isepdgt(coef2,g,L,a,2*M,0);
halfmod=exp(pi*i*(0:L-1).'/(2*M))/sqrt(2);
f=f.*repmat(halfmod,1,W);
if isreal(coef) && isreal(g)
f=real(f);
end;
|
