Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / linear-algebra-2.2.0 / @kronprod / kronprod.m

diff --git a/octave_packages/linear-algebra-2.2.0/@kronprod/kronprod.m b/octave_packages/linear-algebra-2.2.0/@kronprod/kronprod.m
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+++ b/octave_packages/linear-algebra-2.2.0/@kronprod/kronprod.m
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+## Copyright (C) 2010  Soren Hauberg
+## 
+## 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, 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 file.  If not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} kronprod (@var{A}, @var{B})
+## @deftypefnx{Function File} kronprod (@var{A}, @var{B}, @var{P})
+## Construct a Kronecker product object.
+## XXX: Write proper documentation
+##
+## With two input arguments, the following matrix is represented: kron (A, B);
+##
+## With three input arguments, the following matrix is represented: P * kron (A, B) * P'
+## (P must be a permutation matrix)
+##
+## @end deftypefn
+
+function retval = kronprod (A, B, P)
+  if (nargin == 0)
+    KP.A = KP.B = KP.P = [];
+  elseif (nargin == 2 && ismatrix (A) && ismatrix (B))
+    KP.A = A;
+    KP.B = B;
+    KP.P = [];
+  elseif (nargin == 3 && ismatrix (A) && ismatrix (B))
+#          && strcmp (typeinfo (P), "permutation matrix"))
+    ## XXX: Check that the size of P is correct
+    KP.A = A;
+    KP.B = B;
+    KP.P = P;
+  else
+    print_usage ();
+  endif
+  
+  retval = class (KP, "kronprod");
+endfunction