1 ## Copyright (C) 2002 David Bateman
3 ## This program is free software; you can redistribute it and/or modify it under
4 ## the terms of the GNU General Public License as published by the Free Software
5 ## Foundation; either version 3 of the License, or (at your option) any later
8 ## This program is distributed in the hope that it will be useful, but WITHOUT
9 ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 ## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
13 ## You should have received a copy of the GNU General Public License along with
14 ## this program; if not, see <http://www.gnu.org/licenses/>.
17 ## @deftypefn {Function File} {} cosets (@var{m}, @var{prim})
19 ## Finds the elements of GF(2^@var{m}) with primitive polynomial
20 ## @var{prim}, that share the same minimum polynomial. Returns a
21 ## cell array of the paratitioning of GF(2^@var{m}).
24 function c = cosets(m, prim)
27 prim = 0; ## This flags to use default primitive
29 error ("usage: c = cosets (m [, prim])");
37 f = log(gf(1:n,m,prim));
41 idx = f(t(find(f(t) == min(f(t).x)))).x;
48 c{nc} = gf(sort(exp(gf(set,m,prim)).x),m,prim);
49 found(c{nc}.x) = ones(1,length(c{nc}));