Welcome to mirror list, hosted at ThFree Co, Russian Federation.

trisolve.h « TNT « intern « iksolver « intern - git.blender.org/blender.git - Unnamed repository; edit this file 'description' to name the repository.
summaryrefslogtreecommitdiff
blob: 6a4f6e1a5b3829b0d8ce92e4433e70e7fa220053 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
/**
 * $Id$
 * ***** BEGIN GPL/BL DUAL LICENSE BLOCK *****
 *
 * 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 2
 * of the License, or (at your option) any later version. The Blender
 * Foundation also sells licenses for use in proprietary software under
 * the Blender License.  See http://www.blender.org/BL/ for information
 * about this.
 *
 * 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 program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL/BL DUAL LICENSE BLOCK *****
 */

/*

*
* Template Numerical Toolkit (TNT): Linear Algebra Module
*
* Mathematical and Computational Sciences Division
* National Institute of Technology,
* Gaithersburg, MD USA
*
*
* This software was developed at the National Institute of Standards and
* Technology (NIST) by employees of the Federal Government in the course
* of their official duties. Pursuant to title 17 Section 105 of the
* United States Code, this software is not subject to copyright protection
* and is in the public domain.  The Template Numerical Toolkit (TNT) is
* an experimental system.  NIST assumes no responsibility whatsoever for
* its use by other parties, and makes no guarantees, expressed or implied,
* about its quality, reliability, or any other characteristic.
*
* BETA VERSION INCOMPLETE AND SUBJECT TO CHANGE
* see http://math.nist.gov/tnt for latest updates.
*
*/



// Triangular Solves

#ifndef TRISLV_H
#define TRISLV_H


#include "triang.h"

namespace TNT
{

template <class MaTriX, class VecToR>
VecToR Lower_triangular_solve(/*const*/ MaTriX &A, /*const*/ VecToR &b)
{
    Subscript N = A.num_rows();

    // make sure matrix sizes agree; A must be square

    assert(A.num_cols() == N);
    assert(b.dim() == N);

    VecToR x(N);

    Subscript i;
    for (i=1; i<=N; i++)
    {
        typename MaTriX::element_type tmp=0;

        for (Subscript j=1; j<i; j++)
                tmp = tmp + A(i,j)*x(j);

        x(i) =  (b(i) - tmp)/ A(i,i);
    }

    return x;
}


template <class MaTriX, class VecToR>
VecToR Unit_lower_triangular_solve(/*const*/ MaTriX &A, /*const*/ VecToR &b)
{
    Subscript N = A.num_rows();

    // make sure matrix sizes agree; A must be square

    assert(A.num_cols() == N);
    assert(b.dim() == N);

    VecToR x(N);

    Subscript i;
    for (i=1; i<=N; i++)
    {

        typename MaTriX::element_type tmp=0;

        for (Subscript j=1; j<i; j++)
                tmp = tmp + A(i,j)*x(j);

        x(i) =  b(i) - tmp;
    }

    return x;
}


template <class MaTriX, class VecToR>
VecToR linear_solve(/*const*/ LowerTriangularView<MaTriX> &A, 
            /*const*/ VecToR &b)
{
    return Lower_triangular_solve(A, b);
}
    
template <class MaTriX, class VecToR>
VecToR linear_solve(/*const*/ UnitLowerTriangularView<MaTriX> &A, 
        /*const*/ VecToR &b)
{
    return Unit_lower_triangular_solve(A, b);
}
    


//********************** Upper triangular section ****************

template <class MaTriX, class VecToR>
VecToR Upper_triangular_solve(/*const*/ MaTriX &A, /*const*/ VecToR &b)
{
    Subscript N = A.num_rows();

    // make sure matrix sizes agree; A must be square

    assert(A.num_cols() == N);
    assert(b.dim() == N);

    VecToR x(N);

    Subscript i;
    for (i=N; i>=1; i--)
    {

        typename MaTriX::element_type tmp=0;

        for (Subscript j=i+1; j<=N; j++)
                tmp = tmp + A(i,j)*x(j);

        x(i) =  (b(i) - tmp)/ A(i,i);
    }

    return x;
}


template <class MaTriX, class VecToR>
VecToR Unit_upper_triangular_solve(/*const*/ MaTriX &A, /*const*/ VecToR &b)
{
    Subscript N = A.num_rows();

    // make sure matrix sizes agree; A must be square

    assert(A.num_cols() == N);
    assert(b.dim() == N);

    VecToR x(N);

    Subscript i;
    for (i=N; i>=1; i--)
    {

        typename MaTriX::element_type tmp=0;

        for (Subscript j=i+1; j<i; j++)
                tmp = tmp + A(i,j)*x(j);

        x(i) =  b(i) - tmp;
    }

    return x;
}


template <class MaTriX, class VecToR>
VecToR linear_solve(/*const*/ UpperTriangularView<MaTriX> &A, 
        /*const*/ VecToR &b)
{
    return Upper_triangular_solve(A, b);
}
    
template <class MaTriX, class VecToR>
VecToR linear_solve(/*const*/ UnitUpperTriangularView<MaTriX> &A, 
    /*const*/ VecToR &b)
{
    return Unit_upper_triangular_solve(A, b);
}


} // namespace TNT

#endif
// TRISLV_H