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comparison src/DLD-FUNCTIONS/kron.cc @ 3910:79a90a0f0eff

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[project @ 2002-04-25 05:36:52 by jwe]
author jwe
date Thu, 25 Apr 2002 05:36:53 +0000
parents
children 8389e78e67d4
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3909:e54140b9ebe1 3910:79a90a0f0eff
1 /*
2
3 Copyright (C) 2002 Paul Kienzle
4
5 This file is part of Octave.
6
7 Octave is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 2, or (at your option) any
10 later version.
11
12 Octave is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with Octave; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20
21 */
22
23 #ifdef HAVE_CONFIG_H
24 #include <config.h>
25 #endif
26
27 #include "dMatrix.h"
28 #include "CMatrix.h"
29
30 #include "defun-dld.h"
31 #include "error.h"
32 #include "oct-obj.h"
33
34 #if !defined (CXX_NEW_FRIEND_TEMPLATE_DECL)
35 extern void
36 kron (const Array2<double>&, const Array2<double>&, Array2<double>&);
37
38 extern void
39 kron (const Array2<Complex>&, const Array2<Complex>&, Array2<Complex>&);
40 #endif
41
42 template <class T>
43 void
44 kron (const Array2<T>& A, const Array2<T>& B, Array2<T>& C)
45 {
46 C.resize (A.rows () * B.rows (), A.columns () * B.columns ());
47
48 int Ac, Ar, Cc, Cr;
49
50 for (Ac = Cc = 0; Ac < A.columns (); Ac++, Cc += B.columns ())
51 for (Ar = Cr = 0; Ar < A.rows (); Ar++, Cr += B.rows ())
52 {
53 const T v = A (Ar, Ac);
54 for (int Bc = 0; Bc < B.columns (); Bc++)
55 for (int Br = 0; Br < B.rows (); Br++)
56 C.xelem (Cr+Br, Cc+Bc) = v * B.elem (Br, Bc);
57 }
58 }
59
60 template void
61 kron (const Array2<double>&, const Array2<double>&, Array2<double>&);
62
63 template void
64 kron (const Array2<Complex>&, const Array2<Complex>&, Array2<Complex>&);
65
66 DEFUN_DLD (kron, args, nargout, "-*- texinfo -*-\n\
67 @deftypefn {Function File} {} kron (@var{a}, @var{b})\n\
68 Form the kronecker product of two matrices, defined block by block as\n\
69 \n\
70 @example\n\
71 x = [a(i, j) b]\n\
72 @end example\n\
73 \n\
74 For example,\n\
75 \n\
76 @example\n\
77 @group\n\
78 kron (1:4, ones (3, 1))\n\
79 @result{} 1 2 3 4\n\
80 1 2 3 4\n\
81 1 2 3 4\n\
82 @end group\n\
83 @end example\n\
84 @end deftypefn")
85 {
86 octave_value_list retval;
87
88 int nargin = args.length ();
89
90 if (nargin != 2 || nargout > 1)
91 {
92 print_usage ("kron");
93 }
94 else if (args(0).is_complex_type () || args(1).is_complex_type ())
95 {
96 ComplexMatrix a (args(0).complex_matrix_value());
97 ComplexMatrix b (args(1).complex_matrix_value());
98
99 if (! error_state)
100 {
101 ComplexMatrix c;
102 kron (a, b, c);
103 retval(0) = c;
104 }
105 }
106 else
107 {
108 Matrix a (args(0).matrix_value ());
109 Matrix b (args(1).matrix_value ());
110
111 if (! error_state)
112 {
113 Matrix c;
114 kron (a, b, c);
115 retval (0) = c;
116 }
117 }
118
119 return retval;
120 }