File: uperm.m

package info (click to toggle)
dynare 4.6.3-4
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 74,896 kB
  • sloc: cpp: 98,057; ansic: 28,929; pascal: 13,844; sh: 5,947; objc: 4,236; yacc: 4,215; makefile: 2,583; lex: 1,534; fortran: 877; python: 647; ruby: 291; lisp: 152; xml: 22
file content (49 lines) | stat: -rw-r--r-- 1,653 bytes parent folder | download
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
function p = uperm(a)
% Return all unique permutations of possibly-repeating array elements
% =========================================================================
% Copyright (C) 2014 Bruno Luong <brunoluong@yahoo.com>
% Copyright (C) 2020 Dynare Team
%
% This file is part of Dynare.
%
% Dynare 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.
%
% Dynare 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 Dynare.  If not, see <http://www.gnu.org/licenses/>.
% =========================================================================
% Original author: Bruno Luong <brunoluong@yahoo.com>, April 20, 2014
% https://groups.google.com/d/msg/comp.soft-sys.matlab/yQKVPTYrv6Q/gw1MzNd9sYkJ
% https://stackoverflow.com/a/42810388

[u, ~, J] = unique(a);
p = u(up(J, length(a)));

function p = up(J, n)
ktab = histc(J,1:max(J));
l = n;
p = zeros(1, n);
s = 1;
for i=1:length(ktab)
    k = ktab(i);
    c = nchoosek(1:l, k);
    m = size(c,1);
    [t, ~] = find(~p.');
    t = reshape(t, [], s);
    c = t(c,:)';
    s = s*m;
    r = repmat((1:s)',[1 k]);
    q = accumarray([r(:) c(:)], i, [s n]);
    p = repmat(p, [m 1]) + q;
    l = l - k;
end
end

end % uperm