--- /dev/null
+## 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} svd (@var{KP})
+## XXX: Write documentation
+## @end deftypefn
+
+function [U, S, V] = svd (KP)
+ if (nargin < 1)
+ print_usage ();
+ endif
+
+ if (!isa (KP, "kronprod"))
+ error ("svd: input must be of class 'kronprod'");
+ endif
+
+ ## XXX: I don't think this works properly for non-square A and B
+
+ if (nargout <= 1)
+ ## Only singular values were requested
+ S_A = svd (KP.A);
+ S_B = svd (KP.B);
+ U = sort (kron (S_A, S_B), "descend");
+ elseif (nargout == 3)
+ ## The full SVD was requested
+ [U_A, S_A, V_A] = svd (KP.A);
+ [U_B, S_B, V_B] = svd (KP.B);
+
+ ## Compute and sort singular values
+ [sv, idx] = sort (kron (diag (S_A), diag (S_B)), "descend");
+
+ ## Form matrices
+ S = resize (diag (sv), [rows(KP), columns(KP)]);
+ #Pu = eye (rows (KP)) (idx, :);
+ U = kronprod (U_A, U_B, idx);
+ #Pv = eye (columns (KP)) (idx, :);
+ V = kronprod (V_A, V_B, idx);
+ else
+ print_usage ();
+ endif
+endfunction