1function [D, err] = A_times_B_kronecker_C(A,B,C)
2
3%@info:
4%! @deftypefn {Function File} {[@var{D}, @var{err}] =} A_times_B_kronecker_C (@var{A},@var{B},@var{C})
5%! @anchor{kronecker/A_times_B_kronecker_C}
6%! @sp 1
7%! Computes A*kron(B,C).
8%! @sp 2
9%! @strong{Inputs}
10%! @sp 1
11%! @table @ @var
12%! @item A
13%! mA*nA matrix of doubles.
14%! @item B
15%! mB*nB matrix of doubles.
16%! @item C
17%! mC*nC matrix of doubles.
18%! @end table
19%! @sp 2
20%! @strong{Outputs}
21%! @sp 1
22%! @table @ @var
23%! @item D
24%! mA*(nC*nB) or mA*(nB*nB) matrix of doubles.
25%! @item err
26%! Integer scalar equal to zero (if all goes well).
27%! @end table
28%! @sp 2
29%! @strong{Remarks}
30%! @sp 1
31%! [1] This routine is called by Dynare if and only the mex version is not compiled (also used for testing purposes).
32%! @sp 1
33%! [2] This routine can be called with three or four arguments. In the first case A*kron(B,B) is computed.
34%! @sp 2
35%! @strong{This function is called by:}
36%! @sp 1
37%! @ref{kronecker/sparse_hessian_times_B_kronecker_C}, @ref{dr1}, @ref{simult_}
38%! @sp 2
39%! @strong{This function calls:}
40%!
41%! @end deftypefn
42%@eod:
43
44% Copyright (C) 1996-2012 Dynare Team
45%
46% This file is part of Dynare.
47%
48% Dynare is free software: you can redistribute it and/or modify
49% it under the terms of the GNU General Public License as published by
50% the Free Software Foundation, either version 3 of the License, or
51% (at your option) any later version.
52%
53% Dynare is distributed in the hope that it will be useful,
54% but WITHOUT ANY WARRANTY; without even the implied warranty of
55% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
56% GNU General Public License for more details.
57%
58% You should have received a copy of the GNU General Public License
59% along with Dynare.  If not, see <http://www.gnu.org/licenses/>.
60
61% Original author: stephane DOT adjemian AT univ DASH lemans DOT fr
62
63% Chek number of inputs and outputs.
64if nargin>4 || nargin<3
65    error('A_times_B_kronecker_C takes 3 or 4 input arguments and provides 2 output arguments.')
66end
67
68
69% Get & check dimensions. Initialization of the output matrix.
70[mA,nA] = size(A);
71[mB,nB] = size(B);
72if nargin == 4
73    [mC,nC] = size(C);
74    if mB*mC ~= nA
75        error('Input dimension error!')
76    end
77    D = zeros(mA,nB*nC);
78    loop = (mB*nB*mC*nC > 1e7);
79else
80    if mB*mB ~= nA
81        error('Input dimension error!')
82    end
83    D = zeros(mA,nB*nB);
84    loop = (mB*nB*mB*nB > 1e7);
85end
86% Computational part.
87if loop
88    if nargin == 4
89        k1 = 1;
90        for i1=1:nB
91            for i2=1:nC
92                D(:,k1) = A * kron(B(:,i1),C(:,i2));
93                k1 = k1 + 1;
94            end
95        end
96    else
97        k1 = 1;
98        for i1=1:nB
99            for i2=1:nB
100                D(:,k1) = A * kron(B(:,i1),B(:,i2));
101                k1 = k1 + 1;
102            end
103        end
104    end
105else
106    if nargin == 4
107        D = A * kron(B,C);
108    else
109        D = A * kron(B,B);
110    end
111end
112err = 0;
113