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[project @ 1993-08-08 01:13:40 by jwe] Initial revision
author jwe
date Sun, 08 Aug 1993 01:13:40 +0000
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children d68036bcad4c
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0:22412e3a4641 1:78fd87e624cb
1 // tc-inv.cc -*- C++ -*-
2 /*
3
4 Copyright (C) 1993 John W. Eaton
5
6 This file is part of Octave.
7
8 Octave is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by the
10 Free Software Foundation; either version 2, or (at your option) any
11 later version.
12
13 Octave is distributed in the hope that it will be useful, but WITHOUT
14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with Octave; see the file COPYING. If not, write to the Free
20 Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
21
22 */
23
24 #ifdef __GNUG__
25 #pragma implementation
26 #endif
27
28 #include "Matrix.h"
29
30 #include "tree-const.h"
31 #include "user-prefs.h"
32 #include "gripes.h"
33 #include "error.h"
34
35 #ifdef WITH_DLD
36 tree_constant *
37 builtin_inv (tree_constant *args, int nargin, int nargout)
38 {
39 tree_constant *retval = new tree_constant [2];
40 retval[0] = inverse (args[1]);
41 return retval;
42 }
43 #endif
44
45 tree_constant
46 inverse (tree_constant& a)
47 {
48 tree_constant retval;
49
50 tree_constant tmp = a.make_numeric ();
51
52 int nr = tmp.rows ();
53 int nc = tmp.columns ();
54 if (nr == 0 || nc == 0)
55 {
56 int flag = user_pref.propagate_empty_matrices;
57 if (flag < 0)
58 gripe_empty_arg ("inverse", 0);
59 else if (flag == 0)
60 gripe_empty_arg ("inverse", 1);
61 }
62
63 Matrix mtmp;
64 if (nr == 0 && nc == 0)
65 return tree_constant (mtmp);
66
67 switch (tmp.const_type ())
68 {
69 case tree_constant_rep::matrix_constant:
70 {
71 Matrix m = tmp.matrix_value ();
72 if (m.rows () == m.columns ())
73 {
74 int info;
75 double rcond = 0.0;
76 Matrix minv = m.inverse (info, rcond);
77 if (info == -1)
78 message ("inverse",
79 "matrix singular to machine precision, rcond = %g",
80 rcond);
81 else
82 retval = tree_constant (minv);
83 }
84 else
85 gripe_square_matrix_required ("inverse");
86 }
87 break;
88 case tree_constant_rep::scalar_constant:
89 {
90 double d = 1.0 / tmp.double_value ();
91 retval = tree_constant (d);
92 }
93 break;
94 case tree_constant_rep::complex_matrix_constant:
95 {
96 ComplexMatrix m = tmp.complex_matrix_value ();
97 if (m.rows () == m.columns ())
98 {
99 int info;
100 double rcond = 0.0;
101 ComplexMatrix minv = m.inverse (info, rcond);
102 if (info == -1)
103 message ("inverse",
104 "matrix singular to machine precision, rcond = %g",
105 rcond);
106 else
107 retval = tree_constant (minv);
108 }
109 else
110 gripe_square_matrix_required ("inverse");
111 }
112 break;
113 case tree_constant_rep::complex_scalar_constant:
114 {
115 Complex c = 1.0 / tmp.complex_value ();
116 retval = tree_constant (c);
117 }
118 break;
119 default:
120 break;
121 }
122 return retval;
123 }
124
125 /*
126 ;;; Local Variables: ***
127 ;;; mode: C++ ***
128 ;;; page-delimiter: "^/\\*" ***
129 ;;; End: ***
130 */