X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?a=blobdiff_plain;f=octave_packages%2Flinear-algebra-2.2.0%2F%40kronprod%2Ftimes.m;fp=octave_packages%2Flinear-algebra-2.2.0%2F%40kronprod%2Ftimes.m;h=249e761a75cb8e445fd4559cef1a41b7ecfa2dcb;hb=f5f7a74bd8a4900f0b797da6783be80e11a68d86;hp=0000000000000000000000000000000000000000;hpb=1705066eceaaea976f010f669ce8e972f3734b05;p=CreaPhase.git

diff --git a/octave_packages/linear-algebra-2.2.0/@kronprod/times.m b/octave_packages/linear-algebra-2.2.0/@kronprod/times.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} times (@var{KP})
+## XXX: Write documentation
+## @end deftypefn
+
+function retval = times (M1, M2)
+  ## Check input
+  if (nargin == 0)
+    print_usage ();
+  elseif (nargin == 1)
+    ## This seems to be what happens for full and sparse matrices, so we copy this behaviour
+    retval = M1;
+    return;
+  endif
+  
+  if (!ismatrix (M1) || !ismatrix (M2))
+    error ("times: input arguments must be matrices");
+  endif
+  
+  if (!size_equal (M1, M2))
+    error ("times: nonconformant arguments (op1 is %dx%d, op2 is %dx%d)",
+           rows (M1), columns (M1), rows (M2), columns (M2));
+  endif
+
+  ## Take action depending on input types
+  M1_is_KP = isa (M1, "kronprod");
+  M2_is_KP = isa (M2, "kronprod");
+  
+  ## Product of Kronecker Products
+  ## Check if the size match such that the result is a Kronecker Product
+  if (M1_is_KP && M2_is_KP && size_equal (M1.A, M2.A) && size_equal (M1.B, M2.B))
+    retval = kronprod (M1.A .* M2.A, M1.B .* M2.B);
+  elseif (isscalar (M1) || isscalar (M2)) # Product of Kronecker Product and scalar
+    retval = M1 * M2; ## Forward to mtimes.
+  else # All other cases.
+    ## Form the full matrix or sparse matrix of both matrices
+    ## XXX: Can we do something smarter here?
+    if (issparse (M1))
+      M1 = sparse (M1);
+    else
+      M1 = full (M1);
+    endif
+    
+    if (issparse (M2))
+      M2 = sparse (M2);
+    else
+      M2 = full (M2);
+    endif
+    
+    retval = M1 .* M2;
+  endif
+endfunction